Solar PV - Save Money & Shrink Carbon Footprint

[NeilBlanchard]

We have been driving EV's for 3 1/2 years, and we are now using a heat pump for most of heating our house, as well. We got a solar PV system installed yesterday, and it should soon be generating a large amount electricity, to offset our use. The system is Sunpower 327 watt panels (about 20% efficient), and it is warranted for 25 years. The system will pay for itself in just over 5 years, with all the incentives, and in less than 10 years without them.

It is a 10kW system on the AC output, and the estimated annual output is just under 13MWh.

We have expensive electricity here in Massachusetts - we pay between 18¢ and 22¢ total per kWh (both generation and distribution costs); and we also have chosen to pay another 2.4¢ / kWh to support renewable generation. Even with these costs, driving our two EV's (Bolt EV and e-Golf) cost us only about 4.5¢ / mile.

Here's the roof panels, on our reconstructed roof (which is still in process):




And the equipment in the basement:




I am really looking forward to our reduced electric bill, and our reduced carbon footprint.

[SparkE]

Neil - your photos aren't showing.

[oilerlord]

The system is Sunpower 327 watt panels (about 20% efficient), and it is warranted for 25 years. The system will pay for itself in just over 5 years, with all the incentives, and in less than 10 years without them.

It is a 10kW system on the AC output, and the estimated annual output is just under 13MWh.

We have expensive electricity here in Massachusetts - we pay between 18¢ and 22¢ total per kWh (both generation and distribution costs); and we also have chosen to pay another 2.4¢ / kWh to support renewable generation. Even with these costs, driving our two EV's (Bolt EV and e-Golf) cost us only about 4.5¢ / mile.

Hey Neil,

Congrats on the PV system. We're using 9.23 kW of older SunPower SPR-225's. Here's a photof of our system during its installation:



Those must be quite the incentives for an ROI of 5 years and/or you got a steal on what is otherwise pricey gear. If you have a moment, please take us through your math. It would suggest that someone that lives in sunny SoCal paying upwards of $0.40 per kWh would have an ROI of ~2 years despite the installation of one of the most expensive PV systems on the market. Are you putting "not buying gasoline" into the equation?

To your point, savings isn't the only reason to install solar. I only pay ~ 4 cents/kWH on a spot market plan. We may never see our solar pay for itself.

[IMAdolt]

The system is Sunpower 327 watt panels (about 20% efficient), and it is warranted for 25 years. The system will pay for itself in just over 5 years, with all the incentives, and in less than 10 years without them.

It is a 10kW system on the AC output, and the estimated annual output is just under 13MWh.

We have expensive electricity here in Massachusetts - we pay between 18¢ and 22¢ total per kWh (both generation and distribution costs); and we also have chosen to pay another 2.4¢ / kWh to support renewable generation. Even with these costs, driving our two EV's (Bolt EV and e-Golf) cost us only about 4.5¢ / mile.

Hey Neil,

Congrats on the PV system. We're using 9.23 kW of older SunPower SPR-225's. Here's a photof of our system during its installation:



Those must be quite the incentives for an ROI of 5 years and/or you got a steal on what is otherwise pricey gear. If you have a moment, please take us through your math. It would suggest that someone that lives in sunny SoCal paying upwards of $0.40 per kWh would have an ROI of ~2 years despite the installation of one of the most expensive PV systems on the market. Are you putting "not buying gasoline" into the equation?

To your point, savings isn't the only reason to install solar. I only pay ~ 4 cents/kWH on a spot market plan. We may never see our solar pay for itself.

In this part BC were 8 cents low tier and 12 cents high tier rate plus running fees, it's safe to assume with grid tie you'd never bump up into the 2nd tier and utilities buy back surplus power at I believe 10 cents as a credit payed back in cash yearly, my maths on a wholesale self installed 5ish kw system put the ROI at about 8 years, and 10-12 years for a professionally installed system (hard to get solid estimates on that).

Sounds pretty good but I'm just not sure about putting it onto a house I'm thinking of maybe selling but it brings up the question of what a substantial solar system does to the resale value or "sellability" of a home?

If you had 2 identical houses side by side on the same street, one with a solar system grid tied sized to average 100% usage how much extra would you pay for that house?

[NeilBlanchard]

Sorry about the picture links - I tried to use Google where my phone uploaded them. I will try to fix them later today.

We are paying $38,351, plus interest. The loan is 6.24% for 180 months. We can make a lump sum payment within the first 18 months to re-amortize the loan. So, we can take our tax refund next year and pay the loan principal down. This will save us a lot of money.

We get $1,000 cash rebate from the state, and 30% tax credit from the federal government. We will save half to three quarters of our electric bill, which is lot.

SREC's (carbon credits that electric companies bid on) could pay us between $170-$320 / MWh. So that could pay between $2,200 and $4,100 per year. We are getting into the 80% SREC program - in a few months, we would be getting 60%.

[mchapmon]

Congratulations Neil. I think it is a fantastic investment in your future

We did our in reverse order. A while back, and a couple years apart, we installed a pair of solar arrays that add up to 6810 nameplate watts. It has been a decision that I'm glad we made.

With the new car, I'm starting to daydream about adding more solar. We are still learning about our Bolt and like it more than I expected. Plans include installing a Clipper Creek EVSE soon. Until then we're doing ok with the provided portable charge cord.

[oilerlord]

In this part BC were 8 cents low tier and 12 cents high tier rate plus running fees, it's safe to assume with grid tie you'd never bump up into the 2nd tier and utilities buy back surplus power at I believe 10 cents as a credit payed back in cash yearly, my maths on a wholesale self installed 5ish kw system put the ROI at about 8 years, and 10-12 years for a professionally installed system (hard to get solid estimates on that).

Sounds pretty good but I'm just not sure about putting it onto a house I'm thinking of maybe selling but it brings up the question of what a substantial solar system does to the resale value or "sellability" of a home?

If you had 2 identical houses side by side on the same street, one with a solar system grid tied sized to average 100% usage how much extra would you pay for that house?

As far as ROI, that sounds about right, but SunPower is pricey stuff. When I started we were paying 8 cents per kWH / 12 cents including fees, taxes, etc. I sourced the modules on the used market, bought the inverters & racking wholesale, and helped with the installation,but even then the ROI was still 11-13 years. At 4 cents / 6 cents including fees, we may not be in this house long enough for the solar to pay for itself. Unless you're paying big $/kWH, or otherwise get the gear for a steal, I think the "save money" part of solar is a little bit of a misnomer for the average Joe looking to put some PV on his roof.

I've thought about how solar affects resale too, and I know there's a lot of links on the Internet both touting the pros & cons for resale but I think it still comes down to finding the right buyer that values solar in more ways than one. That may not be as easy.

[NeilBlanchard]

I fixed my pictures.