Really: Solar Is Actually Cheaper than PG&E

In October of 2009, we added another 1.4 kW to our roof system via an additional 7 panels and second inverter. Though our initial 3.7kW system zeroed out our annual actual use cost for electricity from P G & E, I wanted to be ready for going to electric and plug-in electric hybrid cars…and to take advantage of the full 30% Federal Tax Credit for 2009 onwards AND the California passed requirement that utilities PAY BACK IN CASH for excess production from home-based systems. I anticipate that our additional 1.4 kW will produce around a $300 or so annual payback for the first year, before the electric cars arrive, and after the vehicle transition our gasoline bills will drop about $100/month with that new vehicle drive systems. With the addition of the second inverter, both systems are tied together and now upload output records 4X per hour to a inside home monitor AND to a corporate website that I can access from anywhere in the world. This monitoring even records the separate production from each of my systems, so I can compare the “per panel” output for the slight differences in how the two systems are configured on my roof.

JJ – re: “I see quotes for solar PV for typical houses in Mass upwards to $80K for the whole job, at that rate the loan interest would be many times the electric bill.”

Yes, it might be, in MA.

In CA where total quotes are lower (because our insolation is better), and our utility rate rise is 6.7%,then if you can get an interest rate of under 6.7% (AND because you get the interest back next year as a tax deduction on a second mortgage loan), it does cost less than PG&E over the 25 year loan life.

But each state is different. You should get a solar quote in your state.

JJ, yes, you are correct that DIY is cheaper. Half the cost of solar is getting guys on your roof. Its like any roofing job.

And in PG&E territory, yes it can be very cost effective taking just a portion off the grid,because as George Parrott (up-thread) notes: the tiered pricing means that a modest baseline usage in PG&E territory costs much less per kwh than high usage.

Our base is around 11 cents per kwh for the first 260 or so (varies by neighborhood) kwhs.

I see quotes for solar PV for typical houses in Mass upwards to $80K for the whole job, at that rate the loan interest would be many times the electric bill.

On Ebay there are many suppliers of the PV tiles that you solder together and build into frames. These sheets (3″x6″) sell for close to a $1/Watt. With the frames and some batteries and converter it looks feasible to build a 1KW trial system for $2K or so in parts. Getting it on the roof is another matter. No my time isn’t worth much these days (thanks to EE out sourcing).

I would only take half the house off grid, mostly the predictable electronics load by adding a few “solar” AC outlets. Going fully off grid for peaky loads like the washer or fridge probably isn’t worth it for now, but half off would half the bill. Then again replacing some high power appliances with newer lower power ones would give similar savings.

Susan,

SHAME ON YOU!

If you were on Wall Street, people would be saying you should be put in jail for that kind of misleading advertising.

You obviously mention, but totally ignore the interest cost in your calculations, and you build in an inflation rate that is totally ridiculous in this economic environment. [SK: The inflation rate in electric prices is a matter of public record for each state: CA 6.7%. I agree it is ridiculous, and has no relation to the larger economy, but it is factual ]

It is deceptive to say the time value of money clouds the issue because you are going to have to pay for energy. You also ARE going to have to pay interest, or forego the interest you could have earned.

[SK: ?? I included the interest for a 20 year loan ]

I hope you are not one of the people excoriating the prime-loan brokers. You have become one of them!

SHAME ON YOU.

Mark

Solar and other renewable energy solution, for space or water heating is definitely a future.

I have seen numerous comments regarding the best solution for water heating, gas, electric, condensation, fuel cells, solar… and it all depends how much money you want to spend. Everything spins around your budget.

Your acceptance of a new (read green/renewable) technology is directly related to how much money you want to spend. Thinking long term… today with money shortage… it is tough.

But, people like to experiment, spend minimum or use parts found in the garage to build a solar water heater for example. I like ideas and designs of cheap and functional heating systems.

Some ideas can be found here, http://www.hot-water-heaters-reviews.com/build-solar-water-heater.html, and many more to come.

Cheers,

Zee

We went to solar PV during 2008, before the full 30% tax credit without limits. Our home system is rated at 3.7 kW (dc) installed as an awning off the south facing roof of our 2 story home. It has reduced our annual TOTAL to P G & E to ZERO for the year of actual use. We still pay the monthly connect fee of around $13 but….before PV installation our monthly bills averaged $250/month. We eagerly got bids and installed the PV system (and a solar water heater system) after our 3rd month utility bills in this new house served fully by P G & E, as our previous 24 years of electric service was from Sacramento’s SMUD. Our last month in the old, SMUD served house, was virtually the same kW total as our first month in the new house (PG & E) and the PG & E electric total was FOUR TIMES what our SMUD monthly charge was in the old house ! Even without today’s wonderful Federal tax credit, we are happy to be “free” of PG & E tiered charges.

Thank you, Susan.

And I’ve got good news: I can get a geothermal heat pump – I didn’t know they could be retrofitted! (found it at http://www.waterfurnace.com). I needed a new system anyway, and there’s the 30 percent federal tax credit (cap’s been removed), so this will cut my heating, water-heating & cooling costs massively for a comparatively small investment.

My remaining usage may well be manageable by solar once it becomes optimally efficient, since my roof does get some sun.

Another thing I googled & got nothing on: is it possible to make the existing driveway white (I heard DOE Secretary Tsui say we should have white pavement and roofs to reflect back the sun – the amount of CO2 he said would be eliminated if it were done everywhere was astonishing.

If there’s a cost-efficient way to do it to the roof prior to roof replacement, I’d do that (but I’d be surprised). But I did come upon a couple of vague references to painting driveways white, just no further info. (what paint holds up under walking, wildlife, weather and driving?)

It’s exciting, this is really happening.

peace,

Fritzi

Fritzi – sadly, no.

I was originally looking for a picture of a house like yours, because, this actually is the one case where solar won’t pay.

This is encouraging, Susan, but I live in the woods – my home and property are in the shade most of the time, and my roof, to make it worse, faces east and west.

Even if I could be convinced that it would pay to cut down trees, many of those shading my roof are on others’ property (and I live in North Carolina). I’ve been waiting for the full-spectrum film to hit the market, but haven’t heard that it has.

Is solar power viable for me now?

Thank you for what you’re doing.

One issue here in Los Angeles (LADWP) is that we can’t actually zero out our electricity bill. As I understand it, DWP insists on charging about $7.00 a month for electricity even if you use no power at all. AND they’ve been able to finagle out of annualized net metering…they only do net metering on a short term (weekly or monthly, not sure which) basis, which can’t help summer generation to balance out winter usage.

So for someone (like me) who already has a fairly low electricity bill, the economics make less sense.

But I’m looking at it anyway, from an environmental perspective. I want my daughter to live in a clean world.

Susan,

I like to hear from real people that actually went all the way to install a photovoltaic residential “power plant”.

One idea that might appeal to you and the readers is to go solar (or wind as the case may be) on a community scale. It is tough to organize but with a leadership and vision – the community will benefit.

See my page on community wind turbines in Canada to get the picture

http://www.solar-energy-for-home.com/community-wind-turbine.html

Best wishes, Jacob

BTW – The reason I didn’t include the cost of capital (the interest you pay for your loan), is that you deduct the entire interest payment from your taxes each following year – assuming you use a second on your mortgage; in the US homeowners can deduct interest on a mortgage loan.

So the net cost excludes the cost of capital: interest payments.

(These estimates also are the final installed costs minus the California PG&E rebate amount at (depending on design)about $1,550 per KW installed, and the 30% Federal tax credit on the cost of a solar installation, passed this year)