# Thoughts on 'personal' energy use



## Slow1 (Jun 30, 2014)

So getting an electric car and paying attention to how much it is using has me thinking more about my energy use.  What got me started was realizing that if I drive the car 60 miles or so, then the amount of electricity required to bring it to full charge (about 20Kwh) is considerably more than the rest of my house uses in a day (about 16kwh).  Now I am avoiding the question of overall efficiency of electric vs gas, but it does seem that as a proportion of my energy use, transportation is much higher than I had expected.

I've spent quite a bit of time/energy/money trying to reduce our household electric use.  I haven't spent nearly as much trying to optimize/minimize my transportation energy use and perhaps there is a significant amount of savings to be had there....

What I have also ignored here is home energy used to heat water (currently oil) and winter heating (wood of course)... so the proportions may not be exactly right - then again I've not calculated our other vehicle into the mix either.

If my results are reflective of others, perhaps there could be tangible savings in encouraging more prudent use of personal transportation.  (Yes I realize public transportation is wonderful if you have it)  Anyone else had thoughts on this line? I've heard for years that one should plan trips etc, but never really did the math on the value....


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## begreen (Jun 30, 2014)

You are doing well but need to add the energy consumed for hot water and heating to have a complete picture. Then start working on the food you eat and especially the beverages consumed. A whole lot more energy is used to move wine and beer from Europe than to move it from local sources.


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## chrispr1 (Jun 30, 2014)

Are you looking at this from a money-saving perspective or an environmental perspective?

I keep track of my home electrical usage very closely and I'm at about 12.5kwh/day over the last 18 months, deducting the high and low months.  I've looked into switching suppliers with the deregulation of the supply-side market, but because I'm such a low-use consumer, it amounts to literally a dime per day in savings.  For me, the easiest way to reduce home usage is to turn stuff off, much like if you want better gas mileage, drive slower or drive less.

I've looked at getting solar panels installed, going geothermal, small turbine, but in each case, the initial investment far outweighed the per month savings and I would have to wait years or decades in order to actually see savings in my pocket.  The only thing it would offer is the environmental aspect of doing it, which isn't a priority for me.

I've used public transportation and personal transportation getting to and from work and unless you work typical hours, personal transportation, in my 60mpg coal roller, is a much better choice for me.  I drive 500 miles/week for work and generally don't drive around outside of that.  At some point you reach a point where any additional improvement gives such a small incremental improvement, it gets to be unreasonable or not worthwhile.

What electric car did you get?  I got a chance to drive a Tesla because the salesman threw me the keys but the range on that is woefully inadequate.


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## mithesaint (Jun 30, 2014)

begreen said:


> You are doing well but need to add the energy consumed for hot water and heating to have a complete picture. Then start working on the food you eat and especially the beverages consumed. A whole lot more energy is used to move wine and beer from Europe than to move it from local sources.



I can't find the source, but I remember reading somewhere several years ago that for those of us that live east of the mighty Mississippi river, the carbon footprint of European wines is actually smaller than California wines.  I don't recall the source or the exact details unfortunately.  I think it had something to do with the efficiency of the transportation.


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## begreen (Jun 30, 2014)

The point being, explore local wines and beers. Ohio/NY/PA/IN/IL/ wines in your case are going to have a lower carbon footprint than either CA or European wines.


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## BrotherBart (Jun 30, 2014)

The carbon footprint of getting chitfaced. Now I have seen it all.


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## jebatty (Jul 1, 2014)

> I've spent quite a bit of time/energy/money trying to reduce our household electric use. I haven't spent nearly as much trying to optimize/minimize my transportation energy use and perhaps there is a significant amount of savings to be had there....


 Yes, have given this thought. Our primary goal has been a net 0 house. We heat primarily with wood, and with the 6.5 kwh solar PV and estimated annual production a little over 9000 kwh, the goal is not to exceed kwh usage greater than PV. Except for wood heat, our house is all electric, including supplemental electric heat and dhw. Also will be adding before fall a small solar hot air collector to get some additional heat into our basement walkout to reduce electric heat usage.

We live in a rural area, nearest small town is 15 miles away, and nearest larger town with major shopping is 45 miles away. Plus, 400 miles round trip to see children and grandchildren in Minneapolis-St. Paul. Driving mileage is 30,000-40,000 miles/year. That is very difficult to reduce by much without giving up family. No public transportation alternative. One of our cars averages 29 mpg on the highway and the other 34 mpg.

If we had rapid public transportation between our home and Minneapolis-St. Paul, I would consider using that and basing an electric car at the home of one our children, for our use when visiting and their use when not. But there isn't any reasonable public transportation even for this.


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## woodgeek (Jul 1, 2014)

There are certainly a *lot* of variables.  You can of course use a carbon foot print calculator to try to figure out all the different contributions.  If you don't worry about carbon, you can still think of CO2 as a (good) proxy for fossil energy use or a (rough) proxy for environmental degradation.

I have looked at a few of these calculators and frankly, most of the ones I looked at were really crappy, and gave results which were IMO erroneous.  There is clearly room for improvement, but the one I found that I liked was:

http://coolclimate.berkeley.edu/carboncalculator

It says that my family footprint when I moved into my house in 2005 was pretty typical for my location/income/family size (80 tons CO2/yr), and after home energy improvements and full electrification of my home and 85% of my car miles with wind power, that is cut roughly in half to 40 tons/yr.  Most of the remainder is air travel, food and 'services' we buy from the US economy.  Sounds about right.


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## jebatty (Jul 1, 2014)

I've only begun recently to look at family food consumption as a major C02 source, particularly meat and dairy products, as well as location of supply points for food. Not sure how this is going to work out, but I think reduction of meat and dairy needs serious consideration. Food purchase more local is an option, but the availability of fresh fruits and vegetables would be severely seasonally limited in our northern climate. We also don't can foods, so buying more local and canning would be a whole new venture for us. Seasonal purchases of local fruits/vegetables and freezing would be an option to some extent and would not increase energy usage so long as we don't add any freezer capacity to what we already have.


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## woodgeek (Jul 1, 2014)

The best studies I have seen suggest that for most foods (excluding those few shipped by air), the energy/carbon associated with food transport is only ~10% of that required to produce it in the first place.  In some cases, it requires less energy to grow something in a warmer climate and ship it north than to produce it locally in a colder climate.

http://shrinkthatfootprint.com/food-miles

So, its not as easy as just buying local. I think it would be a good idea to avoid foods that were likely airshipped, like anything with a short shelf life from another continent.  Otherwise, I don't worry about 'food miles'.

Reducing food wastage is a bigger area for improvement.  And reducing meat/dairy IF you are willing.


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## Slow1 (Jul 1, 2014)

begreen said:


> You are doing well but need to add the energy consumed for hot water and heating to have a complete picture.



Agreed.  Will be easier for the DHW soon as I'm planning to install a Geyser heat pump - if it is up to the task that should eliminate my oil for hot water burn at least during the summer.  Going almost all electric makes it easier to 'see' the relative usages...



begreen said:


> hen start working on the food you eat and especially the beverages consumed. A whole lot more energy is used to move wine and beer from Europe than to move it from local sources.



I guess I"m ahead on the drinks - I generally only drink tap water.  Occasional soda when out.  Food is so much harder for me as the time required to 'source locally' or the increased cost  just put it out of reach (remember we're chasing 4 small ones!).



chrispr1 said:


> Are you looking at this from a money-saving perspective or an environmental perspective?



Yes.  By nature I don't like to waste things.  Saving money helps to drive other savings.  I agree that there is a diminishing return on such things - I'm out of practical ways to reduce our home electric usage.  We have LED's in almost all fixtures we use; kids (and adults) are well trained in turning off unused lights.  TV is rarely on and has a power strip to cut all power etc...  Thus my surprise at how much we use driving about.



chrispr1 said:


> What electric car did you get? I got a chance to drive a Tesla because the salesman threw me the keys but the range on that is woefully inadequate.


I bought a Leaf - see my other thread if you are interested in details.

Ok, so you drive 500 miles per week and a 300 mile range is 'woefully inadequate'? You do realize one is supposed to charge each night?    I'm clearly missing something there.

I have a goal reduce or fully eliminate fossil fuel burning from our daily life.  There is something satisfying knowing that the power we use is primarily from solar via the PV array.  Of course, now that we're using it for the car our surplus production is likely to be gone and the discussion of filling the last piece of our south roof face will be reopened.


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## jebatty (Jul 1, 2014)

Food transport probably is not the primary cost. For meat: the use of water for the animal and for irrigation of crops, and then the carbon footprint of fuel to plant and harvest the crops (corn), fertilizers, herbicides, pesticides is large -- and the air/soils/water pollution is high.


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## woodgeek (Jul 1, 2014)

Slow1 said:


> Ok, so you drive 500 miles per week and a 300 mile range is 'woefully inadequate'? You do realize one is supposed to charge each night?    I'm clearly missing something there.



Perhaps he merely listens to the media.

Much of the auto-related popular press has panned all EVs, often for comedic effect, as having so little range as to be useless, and hyped 'range anxiety' as the major theme for their 'lazy journalism' approach.

Heard an NPR story about folks in Philly adding public EV charging stations and then seeing very low usage.  The journalist talks to these folks, then some other journalists, *no* EV owners/drivers (!), and then concludes that the problem is no one is buying EVs.  When of course, there are thousands of EVs in the area (which you can see driving down the road), presumably being charged at home.


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## Slow1 (Jul 1, 2014)

On the subject of range anxiety - I did notice the first day we had the car that we would need to make an adjustment in our thinking.  In our gas car we would generally not go below 1/4 tank before re-filling.  Basically we artificially reduced the range of the car so that we could have more choice about when to go to the gas station and fill up (i.e. wife waiting for me to drive the car...).  Anyway, with the Leaf it is fine to arrive home on empty.  IF we were to adopt the same 1/4 reserve and feel anxious about hitting that then the functionality of the car goes down quite a bit.  

Example - my wife drove it 75 miles the day after we bought it.  She called me concerned when about 1/2 way home as it was in that last quarter of capacity.  Another call when the "low batter" indicator came on (about 20%), then a "I think I may just make it" when about home.  She arrived home with 9% battery remaining - enough for at least 5 miles more.  A close call?  Not really, just using the car to full potential.  Rest of week she made the same trip 4 more times.  The last time I asked her if the low battery indicator came on - her response "I didn't pay attention because I know it will make it".  Interesting - range anxiety was pretty bad that first drive, but clearly vanished within a few days.

Another example - I had to take my daughter to the airport on Saturday.  It is just about 42 miles per google maps.  I drove there conservatively (tried to stay in speed limit or at least under 70 on the highway.  Arrived with 57% remaining indicated.  Plugged into charging station there while walking he into the airport and was indicating 80% (+23% in about an hour) when I came out and left.  I figured plenty of power so I drove 'normal' on the way home (i.e. traffic speed) and had 25% indicated on return.  Extrapolating the numbers it appears I may well have been able to go both ways without charging, perhaps even driving so conservatively.  I had considered this a "risk" trip, but now I am comfortable that it is in range - if I spend any time there then I could likely make a detour on the way back (doesn't happen often on these runs, but nice to know I can).

My point here being that it is easy to have range anxiety if you have no experience to base a sense of trust.  As I have watched the performance of the car it seems remarkably predictable although I can't yet easily articulate the patterns.  Basically (as one would expect) if you drive hard/fast on highway it will have reduced range, drive easy and you use less power.  The best gauge on the car in my opinion is the real time and average Miles/Kwh bars.  If my trip is averaging 4 or more (which is surprisingly easy to do) I can easily get over 80 miles and not hit very low battery warning (I now consider that my 'reserve' and from my reading that may be 10% of range, or another 8 miles).  So, I plan - rarely do I have a need to travel that far in one day, but if on the edge (like the airport run) I look for a charging station.


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## woodgeek (Jul 1, 2014)

Sensible...we haven't used the bottom 20% yet (the bottom two bars out of 12, which are red) but have used the Leaf without concern for all the 'in range' driving we had.  All our regular trips are <50 miles and the rest are >100 miles roundtrip.


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## chrispr1 (Jul 1, 2014)

Slow1 said:


> Ok, so you drive 500 miles per week and a 300 mile range is 'woefully inadequate'? You do realize one is supposed to charge each night?    I'm clearly missing something there.



It wouldn't be for my commuting car; I know they're meant to be charged. If I can't make it up to my camps in Maine or NH nonstop, it's just an expensive car payment. If it were just for work and back that's another story but I can't afford to have a vehicle that doesn't fit a specific niche in my life. 

ETA: I average 30-35k miles per year.


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## Slow1 (Jul 1, 2014)

chrispr1 said:


> It wouldn't be for my commuting car; I know they're meant to be charged. If I can't make it up to my camps in Maine or NH nonstop, it's just an expensive car payment. If it were just for work and back that's another story but I can't afford to have a vehicle that doesn't fit a specific niche in my life.
> 
> ETA: I average 30-35k miles per year.



Well, I can't imagine anyone buying a Tesla for the economy of it.  Just too expensive.  And I agree, unless you happen to be lucky enough to have one of their charging stations on your route, if you do go over the range limit it isn't the car for that trip.  VERY expensive 'extra' car there!  But I wouldn't turn one down if someone wanted to give me one, heh.

But why not for your 'commuting' car?  Seems it would work well for that... (economics above set aside).  IF someone came up with a 300 mile range electric car for less than say $20K would you give it serious consideration?  I would have to imagine most folks could.


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## NE WOOD BURNER (Jul 1, 2014)

It Seems to me a solar panel could maintain your batteries while you are parked at work and extend your range nicely.

http://www.northerntool.com/shop/to...lar-panels-accessories+amorphous-solar-panels


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## Highbeam (Jul 1, 2014)

Slow1 said:


> IF someone came up with a 300 mile range electric car for less than say $20K would you give it serious consideration?  I would have to imagine most folks could.


 
Problem is that I won't spend 20k$ on any car. Let's hope for a decent used market and relatively (5500$?) cheap battery replacements. Until then it is cheaper for me to buy 4$ fuel and get 15mpg commuting to work.


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## begreen (Jul 1, 2014)

Lots of wine and beer is getting drunk without getting hammered.


woodgeek said:


> Perhaps he merely listens to the media.
> 
> Much of the auto-related popular press has panned all EVs, often for comedic effect, as having so little range as to be useless, and hyped 'range anxiety' as the major theme for their 'lazy journalism' approach.
> 
> Heard an NPR story about folks in Philly adding public EV charging stations and then seeing very low usage.  The journalist talks to these folks, then some other journalists, *no* EV owners/drivers (!), and then concludes that the problem is no one is buying EVs.  When of course, there are thousands of EVs in the area (which you can see driving down the road), presumably being charged at home.


I think you will find most EV owners pretty happy with their decision. We are coming up on a year of owning the Volt and have no regrets. We haven't used public charging too much because there is no universal system. Chargpoint and Blink here don't share scanners. It gets to be a pain unless you belong to the same charging club. That shouldn't be. One should have a universal charge card that works on all systems.

HB, some battery replacements are fairly cheap. I think the Volt and the Prius are under $3000. That said you could easily double your gas mileage with a used Honda Civic or similar car and not worry about the battery.


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## Slow1 (Jul 1, 2014)

NE WOOD BURNER said:


> It Seems to me a solar panel could maintain your batteries while you are parked at work and extend your range nicely.
> 
> http://www.northerntool.com/shop/tools/category_alternative-renewable-energy solar-panels-accessories amorphous-solar-panels



Nice in theory... - the largest panel you linked to is 50 watts.  When I charge with the "trickle charger" off 110v, I am drawing about 1200 watts.  So, I suppose in theory I could pull together 24 of those 50 watt kits and get enough to trickle charge (about 3-4 miles per hour) as long as the sun is full on the panels... Of course at 43lbs (kit shipping weight) each that would weigh in at over 1000lbs to load/haul/set up when I get there.

 I think I'll stick to charging from the plugs and enjoy knowledge that my stationary array is feeding into the system.


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## Slow1 (Jul 1, 2014)

begreen said:


> HB, some battery replacements are fairly cheap. I think the Volt and the Prius are under $3000. That said you could easily double your gas mileage with a used Honda Civic or similar car and not worry about the battery.



I'm wondering what the batteries will look like in 8 years or so - our warranty assures us of at least 80% in 8 years or 100K miles.  I wonder if when we go to replace the batteries at that time if the technology will have improved to enough to give significantly greater range for same space.  I can easily imagine a third party option to update the batteries....  Then again, as I understand it the batteries are likely to go in bits and pieces vs a full replacement at once so it may be more like "annual maintenance" of batteries may require replacement of 5% of the cells or something.


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## begreen (Jul 1, 2014)

Yes, I think capacity will increase, but will it be provided in the same form factor as the factory battery? Almost all battery packs are still quite viable for other service after they have finished their normal auto duty cycle. The battery is typically rated to be still at 80% capacity after years of service in the car. I've read that Volt batteries are being tried out for home power backup systems. There could be a robust market here.


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## semipro (Jul 1, 2014)

Along the same lines of drinking locally, eating lower on the food chain has a big impact.  Link to a recent study below. 
http://link.springer.com/article/10.1007/s10584-014-1169-1


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## begreen (Jul 1, 2014)

There are some that say livestock production is the greatest human influence on the planet. 

_"...about 30% of the word’s total ice-free surface — is used *not* to raise grains, fruits and vegetables that are directly fed to human beings, but to support the chickens, pigs and cattle that we eventually eat."_

http://science.time.com/2013/12/16/...vironmental-impact-of-global-meat-production/


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## chrispr1 (Jul 1, 2014)

Slow1 said:


> But why not for your 'commuting' car?  Seems it would work well for that... (economics above set aside).  IF someone came up with a 300 mile range electric car for less than say $20K would you give it serious consideration?  I would have to imagine most folks could.



I'm with another who doesn't spend that kind of money on vehicles. I got my commuter for 25% of retail because it had a bad clutch and it still gets me huge mpg. The EVs are still pretty new in my mind and I'd rather let the early owners cut their teeth on them and would consider them down the line. My baseline would be a range of about 750 miles without a charge which is close to what I get on a full tank of fuel without a car payment, higher insurance rates, or personal property taxes. The economics just don't make sense for me and I'd only be buying one out of social responsibility and the premium right now is pretty steep.


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## peakbagger (Jul 1, 2014)

NE WOOD BURNER said:


> It Seems to me a solar panel could maintain your batteries while you are parked at work and extend your range nicely.
> 
> http://www.northerntool.com/shop/tools/category_alternative-renewable-energy solar-panels-accessories amorphous-solar-panels



Unless the car is parked under a solar carport, using solar panel to trickle charge the car will not amount to much addition in range. Some companies use a solar panel to run ventilation fan to cool the interior at bit so that the AC doesn't have to be run as hard.

By the way, Harbor Freight solar panels are rather infamous for being quite poor quality.


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## woodgeek (Jul 1, 2014)

peakbagger said:


> By the way, Harbor Freight solar panels are rather infamous for being quite poor quality.



And quite expensive too compared to many sources including fleabay.


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## chrispr1 (Jul 1, 2014)

Finally reading through all of the posts and other threads on EVs, I would say that the EV crowd weighs social consciousness and environmental concerns somewhat higher than the actual dollars and cents savings.  With that said, are you buying your electric supply via deregulation (if able) via 100% renewable resources, the traditional supplier, or other renewable sources?  At ~20kwh/day, a 30 day month would be about a ~$120 electric cost at my rates.  How would that compare to what you would spend on fuel and how would the monthly payment/lease on the car factor in on your decision?


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## NE WOOD BURNER (Jul 1, 2014)

Yes the practical application of solar panels for this purpose with the available technology is currently economically not viable. The theory is sound though. I have always thought that the electric motor should power the vehicle and a light weight diesel generator could charge the battery when the wheel generators are not in motion.
Europe has several diesel hybrids that achieve great numbers.  but to me a hybrid is like buying a combination boiler. you give up efficiency unless you focus on one fuel source.
Love the fact that I was born in a time that we studied and talked about these technologies and now I can see many of them in practical applications.


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## woodgeek (Jul 1, 2014)

chrispr1 said:


> Finally reading through all of the posts and other threads on EVs, I would say that the EV crowd weighs social consciousness and environmental concerns somewhat higher than the actual dollars and cents savings.  With that said, are you buying your electric supply via deregulation (if able) via 100% renewable resources, the traditional supplier, or other renewable sources?  At ~20kwh/day, a 30 day month would be about a ~$120 electric cost at my rates.  How would that compare to what you would spend on fuel and how would the monthly payment/lease on the car factor in on your decision?



I got the Leaf EV because it is a very fun, comfy, remarkably low cost of ownership vehicle that suits our needs very well.  I drive aggressively, and get 4 mi/kWh. At my electric rates $0.125/kWh for wind power, that is $0.032/mile for energy.  My wife is using it as a commuter instead of a 22 mpg vehicle that costs $0.17/mi for gas, saving us about $100/mo on fuel.

At your rate of $0.20/kWh, figure 5 cents per mile for energy.  You could match that cost-wise with a gasoline car that got 75 mpg.


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## isipwater (Jul 1, 2014)

Slow1 said:


> So getting an electric car and paying attention to how much it is using has me thinking more about my energy use.  What got me started was realizing that if I drive the car 60 miles or so, then the amount of electricity required to bring it to full charge (about 20Kwh) is considerably more than the rest of my house uses in a day (about 16kwh).  Now I am avoiding the question of overall efficiency of electric vs gas, but it does seem that as a proportion of my energy use, transportation is much higher than I had expected.
> 
> I've spent quite a bit of time/energy/money trying to reduce our household electric use.  I haven't spent nearly as much trying to optimize/minimize my transportation energy use and perhaps there is a significant amount of savings to be had there....
> 
> ...


About three years ago, I decided to get a solar hot water system.  It was been wonderful.  I also live in Eastern MA.  Here is how it works:

My setup is that I have a solar hot water tank that feeds into my existing electric hot water tank.

I turn my electric hot water heater off at the breaker in April and don't need to turn it back on until late September. That is, for 6 months, the solar system basically provides more hot water than we (family of 5) can use.

Then in late Sept. I turn the electric hot water heater back on.  The solar hot water heater still works during fall, winter and early spring by bring up to water temp to about 90F.  That means my electric water heater only has to heat the water 30 more degrees to 120F.

The company I used, I believe, is one of the best solar hot water companies in the nation.  In fact, solar hot water is all they do.  They use high quality German equipment.

Massachusetts has a generous state rebate and tax credit for solar hot water.  My pay back period is calculated to be about 5 years.

The company I used is called New England Solar Hot Water.


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## Slow1 (Jul 2, 2014)

isipwater said:


> About three years ago, I decided to get a solar hot water system. It was been wonderful. I also live in Eastern MA. Here is how it works:
> My setup is that I have a solar hot water tank that feeds into my existing electric hot water tank. ...



I will give that company a call.  I had planned to install solar hot water as well, thus the reserved space on my roof.

The reason that I have not done so this year is that every quote I got had a longer payback period (on the order of 10-12 years) vs a solar PV array that is on the order of 8 years at the worst, then continues to have SREC revenue for another couple years which makes the 10 year ROI even better.  

Solar, then feeding a heat pump, based on my calcs, seems to be a better option and the 'excess' electric during the summer is easier to store on the grid than any excess heat from solar hot water.


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## Slow1 (Jul 2, 2014)

chrispr1 said:


> Finally reading through all of the posts and other threads on EVs, I would say that the EV crowd weighs social consciousness and environmental concerns somewhat higher than the actual dollars and cents savings.  With that said, are you buying your electric supply via deregulation (if able) via 100% renewable resources, the traditional supplier, or other renewable sources?  At ~20kwh/day, a 30 day month would be about a ~$120 electric cost at my rates.  How would that compare to what you would spend on fuel and how would the monthly payment/lease on the car factor in on your decision?



I hesitate to call myself "socially conscious" any more than anyone else.  I think that the "geek appeal" may have had as much to do with my desire to drive electric as anything else.  Lucky for me my wife is very practical and required that the effort make sense too.  For us the Leaf made sense - The net cost was very comparable to a gas car of same size with similar features with the gas 'winning' on range of course.  For our usage pattern of this car (we replaced a small gas car so we could see our use on that one) the range limitation is unlikely to be an issue more than a couple times a year.

We have a PV array that has been running for over two years now and, on average, is over-producing about 900Kwh/year (about 3600 miles worth), thus we currently have about 7200 miles worth of power credit, add this year's production and our first year of driving should be pretty much all come from our array or prior credits.  I hope to expand the array next year enough to cover our driving going forward.  

Our cost on the solar array comes to about $0.10/Kwh over the course of 10 years.  With gas at $3.50/gal and considering 30mpg car this Leaf replaced, that is a 75% savings on gas.  Over the course of 10 years if we drive the car 10,000 miles/year then our fuel savings I would expect to exceed $9,000 (exceed because I tend to believe gas prices will be a bit higher over the course of the next 10 years).  

Now for the fuzzy part - IF one considers the "fuel savings" to be like a rebate on the car, then our 10 year cost for the acquisition after rebates would be about $17K-9K=8K or about $800/year (plus maintenance) or for those who think monthly about $67/mo -  assuming zero scrap value at the end.  Maintenance schedule looks to be quite a bit less expensive annually on the Leaf so if anything that tilts toward the Leaf in costs.  This assume driving the car for the 10 years/100K miles of course and there are lots of other questionable assumptions (thus 'fuzzy') but it is an interesting thought experiment.  A comparable new gas car at $17K comes to about $142/mo plus maintenance using the same analysis, but also has the additional risk of higher fuel costs (note that my electric cost is fixed if pulled from the PV array).  Then of course one doesn't have to pre-buy 10 years worth of gas either so lots of "time value of money" questions can be raised...  

Oh - and If I do the same calc using 5 years, 50K miles I come to an average monthly cost of $206 with zero scrap value (Very unlikely in my opinion), put a modest estimate of $4K resale value at 5 years and the monthly falls to $140.  Tons of assumptions being made here.

Note that I don't calculate in terms of "Monthly payments" as that is financing - i.e. how you buy/rent/invest your cash and adds too many variables for this discussion in my opinion although financing clearly is material in all these things (see prior comment regarding time value of money).


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## maple1 (Jul 2, 2014)

I considered solar hot water, but running some quick numbers made it a no-go for me.

A couple of years ago when I did check it out, I think I was looking at around $3500 after incentives. Our electric hot water heater costs around $20/mo to run, and it only runs about 2 months (the other 10 I heat it with wood). Even streatching that out to 4 months, and more conservatively estimating $25/mo, I would only be looking at $100/year and a 35 year payback period. That's off the cuff - and my wood isn't exactly free. But it is very cheap as long as I still enjoy the exercise. Trying it again with a sharper pencil might reduce the 35 years to something more realistic - but I don't think it would get to anything close to the trigger-pulling range.

Two years ago I was still burning oil for DHW though - looking back, payback compared to that would likely get down to the 8 year area. But that's more on the oil being so bad to start with.


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## isipwater (Jul 2, 2014)

Slow1 said:


> I will give that company a call.  I had planned to install solar hot water as well, thus the reserved space on my roof.
> 
> The reason that I have not done so this year is that every quote I got had a longer payback period (on the order of 10-12 years) vs a solar PV array that is on the order of 8 years at the worst, then continues to have SREC revenue for another couple years which makes the 10 year ROI even better.
> 
> Solar, then feeding a heat pump, based on my calcs, seems to be a better option and the 'excess' electric during the summer is easier to store on the grid than any excess heat from solar hot water.



Massachusetts is the best state in the country for solar hot water incentives right now.

After incentives (state, fed, and rebates), a solar hot water system from New England Solar Hot Water costs $2,557

Also, if you go through Mass Save you can get that amount on a 0% interest loan for 7 years. That is about $30.44 per month.

This is why it made sense for me:

My electric (80 gallon) hot water heater uses 4622 KWH per year.  My electric rate is $.18/KWH.  Therefore, I was spending $831 per year to run the electric hot water heater.

Now, I estimate that I only use 1155 KWH per year for my electric hot water heater, which costs me $208.  Therefore, I am saving about $623 per year.

When I bought my solar hot water system, the cost was about $3500.  Hence, my payback of about 5.5 years.

However, in the last three years, the system cost has come down by almost a third (mainly due to the new state rebate program).

If I would have bought the system this year, my payback would have only been 4.1 years.  Not bad, again with a 0% interest loan via Mass Save.


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## maple1 (Jul 2, 2014)

*My electric (80 gallon) hot water heater uses 4622 KWH per year. My electric rate is $.18/KWH. Therefore, I was spending $831 per year to run the electric hot water heater.*

Do you have anything that might cause above average hot water usage? That is about 2.5-3x what I am estimating (from power bills) our 2 year old 80 gallon HWH uses in the summer months it is used - also for a family of 5 with regular showers & laundry.

How old is the heater? Do you have heat traps on it? Is it sitting right on concrete?

I guess one factor might be that less hot is used in the summer than winter - here at least. I think.


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## woodgeek (Jul 2, 2014)

Interesting.  My SHW quote was $14,000 with a $9000 rebate from US and PA for an out of pocket of $5k.  And might use less electricity (for backup) than a HPWH that cost abut 60% as much installed, despite the rebates.


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## isipwater (Jul 2, 2014)

maple1 said:


> *My electric (80 gallon) hot water heater uses 4622 KWH per year. My electric rate is $.18/KWH. Therefore, I was spending $831 per year to run the electric hot water heater.*
> 
> Do you have anything that might cause above average hot water usage? That is about 2.5-3x what I am estimating (from power bills) our 2 year old 80 gallon HWH uses in the summer months it is used - also for a family of 5 with regular showers & laundry.
> 
> ...


In 2008, I bought a Kenmore 12 year 80 hot water heater. I don't think there is anything unusual about my usage. My figures are based on the Energy Guide attached to the unit.


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## isipwater (Jul 2, 2014)

woodgeek said:


> Interesting.  My SHW quote was $14,000 with a $9000 rebate from US and PA for an out of pocket of $5k.  And might use less electricity (for backup) than a HPWH that cost abut 60% as much installed, despite the rebates.


Check out this link to see how simple this system is and therefore, why it is not that expensive.  By the way, the photo at the top of this page is my actual solar hot water panels on my roof!

http://neshw.com/residential/new-england-drainback-appliance/


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## woodgeek (Jul 2, 2014)

Highbeam said:


> Problem is that I won't spend 20k$ on any car. Let's hope for a decent used market and relatively (5500$?) cheap battery replacements. Until then it is cheaper for me to buy 4$ fuel and get 15mpg commuting to work.



The current price for a replacement Leaf battery is $5500, assuming a salvage value of $1000 on the old battery sold to Nissan.

http://insideevs.com/breaking-nissan-prices-leaf-battery-replacement-5499-new-packs-heat-durable/

And the new vintage batteries are significantly more durable (mostly heat tolerant) than the earlier ones.  Many of the first Leafs are just now showing up as 'used EVs' after their 3 year lease ran out.

And the price of the battery has fallen >50% over the last 3 years.


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## woodgeek (Jul 2, 2014)

isipwater said:


> Check out this link to see how simple this system is and therefore, why it is not that expensive.  By the way, the photo at the top of this page is my actual solar hot water panels on my roof!
> 
> http://neshw.com/residential/new-england-drainback-appliance/



I don't doubt it.  I just can't find anyone to install a system at your prices in my area.  They are claiming the rebates for themselves....their quotes go up and down as the rebates run out and get reinstated.


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## maple1 (Jul 2, 2014)

woodgeek said:


> Interesting.  My SHW quote was $14,000 with a $9000 rebate from US and PA for an out of pocket of $5k.  And might use less electricity (for backup) than a HPWH that cost abut 60% as much installed, despite the rebates.


 
Zoinks - that estimate seems out there.

I was looking at around $5-6k (before any subsidies, etc.) for a two panel system with pump, tank, and funky looking HX that I think also encorporated another pump. Not a drainback system. Installed.


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## dougstove (Jul 5, 2014)

A rural location can quickly cancel the benefits of household energy efficiency.
I have a friend who built a marvellous passive solar house about 7 km outside our tiny town.
I have a much less efficient, older house, but I walk 1 km to our work place, the kids walk to recreations and to the store.
Net, my savings on gas outweigh his savings on heat.


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## begreen (Jul 5, 2014)

That savings can be offset by them with an electric car or a bicycle.


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## Slow1 (Jul 6, 2014)

dougstove said:


> A rural location can quickly cancel the benefits of household energy efficiency.
> I have a friend who built a marvellous passive solar house about 7 km outside our tiny town.
> I have a much less efficient, older house, but I walk 1 km to our work place, the kids walk to recreations and to the store.
> Net, my savings on gas outweigh his savings on heat.



I think that is a very good point.  When we lived in side the city (Boston, JP for the locals) we walked or took public transportation quite a bit.  However, in that case the 100+ year old house with original (none?) insulation probably burned more to heat than we could possibly have driven.  Oh well - balance is the key I suppose.

I've got all the low laying fruit in the house pretty well plucked.  Transportation looks to be another area with the potential for significant progress...


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## Seasoned Oak (Jul 6, 2014)

begreen said:


> There are some that say livestock production is the greatest human influence on the planet.
> 
> _"...about 30% of the word’s total ice-free surface — is used *not* to raise grains, fruits and vegetables that are directly fed to human beings, but to support the chickens, pigs and cattle that we eventually eat."_
> 
> http://science.time.com/2013/12/16/...vironmental-impact-of-global-meat-production/


The simple answer would be to consume the protein in its vegetable form and bypass the whole animal conversion completely.  Easier said than done i have to admit. Though im trying.


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## begreen (Jul 6, 2014)

We were vegetarians for about 20 yrs so it comes easy for us. We now eat some meat or fish a few times a week, but try to keep it at least to WA state grown. Last night's salmon though came from Alaska.


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## Cynnergy (Jul 7, 2014)

My salmon last night came from the cabin's front yard - about 0.1 food miles .  Although it has been in the freezer for almost a year, so that negates the energy savings substantially.  Going to try to can most of our salmon this year.  Can't wait for the season to really start, we've been out a few times but skunked.  Still early yet.  Here fishy fishy fishy...

I've also tried to convince hubby to take up hunting with me.  So far, it's not a priority.  We try to eat vegetarian a few times a week, although I don't think I could ever go vegan - and cheese and egg production still involves a lot of energy.

Meat production on land not suitable for arable crops (rangeland, etc) has a lot less embodied energy than feedlots, although there is an increase in methane emissions I believe.  Gets back to some complicated math when looking at food miles.  One of my friends in Nova Scotia actually calculated that there was less embodied energy in field strawberries from California than in greenhouse-grown local strawberries in his area.  

There is a local farmer interested in using waste heat from the sewage treatment plant for heating greenhouses - I hope that gets off the ground, it would be great.  Then again so would heating greenhouses with the wood waste from forestry operations.  I think it's scandalous that it just gets burned up 'in the field' but I guess transporting it to a plant of some sort for conversion into pellets isn't financially viable for whatever reason.


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## dougstove (Jul 7, 2014)

Cynnergy said:


> Meat production on land not suitable for arable crops (rangeland, etc) has a lot less embodied energy than feedlots,


Yes! The industrial feedlot does alot of damage. People cannot (directly) eat grass, but we could eat the grain that goes to feedlots.
One of the problems with low grade heat sources is the embodied energy of the recovery system can outweigh the gains, unless the payback time is very long.


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## woodgeek (Jul 7, 2014)

Cynnergy said:


> I don't think I could ever go vegan - and cheese and egg production still involves a lot of energy.



Cheese is pretty bad  but eggs are pretty good, can be as good as fish.  Low feed to produce good animal protein.


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## begreen (Jul 7, 2014)

Vegan does not include cheese and egg. And they don't want to know the energy that goes into producing tofu.


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## Cynnergy (Jul 8, 2014)

Oops sorry for the ramble.  I will try to keep it shorter.

BG I never thought about the energy in tofu production, very interesting point...


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## begreen (Jul 8, 2014)

No matter what we do it will have an impact on the planet. We don't need to walk on tip toes, but treading lightly and mindfully is a help.


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## dougstove (Jul 9, 2014)

Payback on solar hot water depends alot upon time of life.
I got a 2 panel glycol unit installed (Thermodynamic) for about $5000, 4 years ago.
But I had 3 teenagers and 4 dogs with various hair habits. 
So the payback compared to electric hotwater was short.


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