Thoughts on 'personal' energy use

[chrispr1]

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.

 

[peakbagger]

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.

 

[woodgeek]

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.

 

[chrispr1]

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?

 

[NE WOOD BURNER]

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.

 

[woodgeek]

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.

 

[isipwater]

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....

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.

 

[Slow1]

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.

 

[Slow1]

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).

 

[maple1]

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.

 

[isipwater]

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.

 

[maple1]

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.

 

[woodgeek]

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.

 

[isipwater]

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.

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.

 

[isipwater]

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/

 

[woodgeek]

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.

 

[woodgeek]

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.

 

[maple1]

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.

 

[dougstove]

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.

 

[begreen]

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

 

[Slow1]

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...

 

[Seasoned Oak]

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.

 

[begreen]

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.

 

[Cynnergy]

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.

 

[dougstove]

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.