My roof is perfect for solar but my electric bills are low. Worth it?

[EatenByLimestone]

I completely understand that. What I question is the future. I'd hate to go into a home equity loan (or line of credit) without a backup on how I'd pay for it if the unexpected happened, such as job loss.

Now, my warning might be totally unnecessary. The gentleman may have twice the needed amount in cash reserves, but doesnt want to go below 6 months of cash reserves to make this investment.

But he might also be living paycheck to paycheck.

I just want to make sure he's thought this through as I've been a mortgage consultant and know they're more than happy enough to sell a mortgage if the numbers work. It often doesn't matter if it's the right decision or not.

Solar prices will continue to come down. There's no harm or shame waiting to make the purchase next year when the price will be lower.

 

[Brian26]

We crunched some numbers yesterday and I think we are going to just outright buy them. We have a budget of $12,500. The house was my grandfathers that he bought brand new in 1958 and we bought it cheap. We love the house, neighbors and town and are here for the long term.

Our average monthly electrical usage is 400 Kwh/month. Does anyone have any numbers in New England for a 5kwh system?

The PVWatts website is estimating 8781 kwh's a year based on my address. Almost double of my average monthly usage.

 

[peakbagger]

Rarely does it make sense to go into the power business on purpose, meaning match your expected yearly generation with your yearly usage. There is a big "but" and that depends on what you use for shoulder season heating. If you have net metering, a mini split is great option for heating your home during shoulder season. I generate a surplus and then use it to run a mini split for heating in the fall and spring when the overnight temps are above 30 degrees and the day time temps warm up. During last years mild winter I didn't run my wood boiler until early December and pretty much stopped burning wood after late march.

 

[DBoon]

You'll get about 80 to 130 kWh/month per installed kW of panel, depending on the month. I'd be shocked if you were able to generate nearly 9000 kWh/year with a 5kW system located in Connecticut. I would expect closer to 7,000 kWh/year with that size in CT. I get about 5800 kWh/year in my Central New York location, but this is a bit cloudier area than most of Connecticut, especially in the winter.

 

[jebatty]

PVWatts provides good estimates but accuracy depends on the validity of the assumptions and parameters inserted into the calculation, plus local weather conditions. In my area of Minnesota annual production is in the range of 1.2-1.4 mWh per 1,000 kWh of DC panel rating (my system is a bit under 1.3mWh/1000kWh), but monthly production for my 12.3kW system ranges from a low of about 300 kWh in December to high of about 1,800-1,900 kWh/month in June/July.

 

[lml999]

Keep in mind that your electric bills will go up over time. With excess power, you can also make different choices -- electric dryer/hot water heater/oven, etc. You might be more inclined to buy an electric car too...

In our case, we expect to be in the house a long time and will find ways to consume the extra capacity.

Of course, even before we install the panels, we are improving the house efficiency. Mass Save consultant came by yesterday and prescribed $4K of insulation upgrades -- top plate sealing, more attic insulation, etc., and installed perhaps $800 of LED bulbs. That $4K of work will cost us $900 out of pocket. As soon as we get an issue with the hot water heater vent addressed, we'll do the insulation work.

The consultant said that the house will be so well sealed that we should install a bathroom fan that runs continuously at low speed (designed for exactly this purpose). Sort of a poor man's air exchanger... Our house isn't tight enough to require an air exhanger...but some air turnover was recommended. Personally I'd prefer to do a formal air exchanger, but SWMBO keeps a tight handle on the budget, particularly for things she doesn't really understand.

Interestingly, Mass Save could have provided us with a *lot* more LED bulbs, but they are not allowed to swap out CF for LED...

They did replace a number of halogen mini spots in the basement with LED and I'm not sure I like the color difference. We'll see if we get used to it, otherwise the halogens might go back in. (They don't take the old bulbs with them....they leave them for the home owner to discard as appropriate).

So, if you have an opportunity for a Mass Save inspection, make sure all the bulbs in your house are incandescent.

 

[velvetfoot]

Does anybody else think it weird that these solar programs seem to be encouraging more electric consumption?
On the other hand, you feel like a sap if you don't take advantage since you're helping to pay for your neighbors' systems.

 

[lml999]

Does anybody else think it weird that these solar programs seem to be encouraging more electric consumption?
On the other hand, you feel like a sap if you don't take advantage since you're helping to pay for your neighbors' systems.

Well...there's a difference between more energy consumption and switching energy sources. If I move from a NG hot water heater to electric, and am consuming electricity generated from my roof...sure I'm consuming more electricity. But I'm consuming less NG and I'm not consuming electricity generated by coal, or NG, or oil, or nukes...

From where I sit, it's a net decrease in traditionally generated power, and a shift to sustainable...

 

[velvetfoot]

You agree with me that you will be consuming more electricity by fuel switching. Electricity is a real time commodity-unless you have batteries or pumped storage generation or the like the load and generation has to be matched. You will be using more electricity than you used to before you switched fuels even on those days, or maybe weeks or months, when the sun doesn't shine, is low in the sky (winter), short days,, etc.

Your local utility has to plan for your new water heater, a/c, electric car, etc, when you can't supply the load. Maybe it serves to level the load over the course of the day when the sun is shining, but the utility still has to have enough capacity to supply load, including the increase, whenever the sun is unavailable.

Net metering is an artificial construct.

 

[lml999]

You agree with me that you will be consuming more electricity by fuel switching.

Agreed. Some of this additional usage may coincide with peak generation time -- central air, for instance.

Conversely, electric car charging might be done only at night.

 

[Dobish]

my parents are right down the street in Clinton, and they put in a system a few years ago. They have a similar sized roof. they end up producing around 120% of their usage, and they are not the most energy efficient folk. They end up getting paid back by their utility company regularly. One of the things to look into is a battery storage system (like tesla's wall system) if you have the space. this way you can actually utilize your solar when you need to turn the lights on!

We have solar on 2 places out here in CO, and on 1 of them we produce 100% of our energy, the other about 10%. We were hoping to be able to produce more, but we were unable to due to our roof design, structure, etc. If I were to have done things differently on that house, I would have not gone through SolarCity and I would have just built a ground unit to produce enough electricity. When we first moved into the house, the average electric bill was $350/month, and we are down to around $75 now +$15/month for the solar.