I thought this might be interesting to some. We have solar installed to power our house. When the Clarity arrived the solar can power both the house and the car...sometimes. It isn't as straight forward as that. We started with a system that was hindered by an undersized inverter so we weren't getting the full benefit of the roof panels. It took a while to convince the contractor to upgrade the inverter. At the same time, with a special deal from the contractor, we added two more panels for a total of 20. Now the system was operating at peak and we began to seriously pump extra power back to the city grid. Hot summer hit (normally 105-112 for several weeks) and the solar system was taxed by the house AC but keeping up. Then the local wildfires hit. The smoke from the wildfires stayed over the city for several weeks. The ash coated the solar panels and blocked the sun. Finally the smoke cleared, we washed the panels for the third time, and our system is once again able to supply more than we need. One would naturally think solar is either sized properly or not. But there are so many variables. For example last year we car pooled with other parents to take kids to school. That cut 25 miles out of each school day for the Clarity. This year the other family can't participate because their house was leveled in the Carr fire. This chart is filled with data from daily readings of our bi-directional electric meter. Until the fires started we were on track to save about $2,500 in house electricity and car gas this year.
Speaking for the multitudes who enjoy your postings, we're very happy your family and home survived that horrible fire. Can you estimate your investment in your solar-electric installation? I'd imagine your pay-back won't take long at $2,500/year. Did the installation cause your property taxes to increase? A lot of people in the supposedly green-thinking city of Ann Arbor where I live are PO'd because our assessor decided to increase taxes on homes with solar panels, even though surrounding cities interpret the state laws differently.
Another thing to keep in mind with solar is that when the temps get really hot, the system doesn't generate as much as it does during milder temps. Just how those things work. The amount of draw on the system is a separate issue. Higher temps = less production.
I'm not home so I don't have the exact figures. The installation was about $30K overall. That included 20 panels, inverter, electrician to install 240V line for the EV charge station, Juice Box 40. Tax credits covered roughly 30%. There was a state rebate too. The city rebated about $1,500 by subtracting that amount monthly from our combined utility bill (sewer water trash electricity). We also had rebates for the Juice box. I estimate out payback is 8 years but due to the crazy solar data I just posted this year won't be as productive as I thought it would be. The other expense wasn't exactly a solar expense but... Our roof was a 30 year type but only 20 years old. The sun is so intense here there is no way it would last 30 years. If we had to pull the solar off to replace the roof it would have been quite expensive. So we had the roof replaced too for about $10K The big bonus was we sized the system for the house. The panels we selected are pretty efficient and produced more than planned, enough to charge the Clarity. So as far as I'm concerned the car charging is free. No news on the property tax going up. Could happen. The downside is if the house does burn down it is unlikely the insurance would fully replace the cost of the system. I did contact the insurance company and plan to increase the coverage so higher premiums will be an additional cost.
The economics of household solar have a lot to do with state and local utility policies and incentives, which are constantly changing, so make sure you have an installer who can guide you through everything. We were able to get in to the last year of a favorable state incentive program here in MA, and with a generous net metering policy, new insulation and a light colored metal roof reflecting summer heat should be able to cover all our use including the Clarity. Where we are, solar installations are exempt from property taxes. Our payback stretches out to 7 years or so for 31 panels on a less-than-ideal roof.
True although even with 110 degrees for a while this summer we had peak performance those days. I suspect the more direct sun on the panels at the vernal equinox helped. Perhaps over 110 degrees (which we didn't have this year) might have shown a reduction. It's important to make sure the panels are raised a good six inches off the roof so air can pass under them. A small benefit is the roof is in the shade under the panels so less heat directly on the roof! Things that can disturb the solar production: - Too much heat - Non optimal sun angle to the panels - Dirty panels - Shade
For us the Clarity tipped the scales in favor of a much shorter payback period. The savings in gas with us averaging 20K miles per year made a big difference. Home on Solar + car on Solar = shorter payback period. Another local benefit is our city runs the electricity grid for the city. They charge $0.15/kWh 24/7. The good news is they pay $0.15 as we pump power back to the grid. The city then acts like a battery for us. Our contract with the city is that will remain the same charge for the life of our solar system or 25 years. Redding CA is the 2nd sunniest city in the USA so it makes a lot of sense to go solar here. Not so much for some other locations across the country. I grew up in Rochester NY - clouds clouds clouds. We may go for several weeks in the summer without seeing a cloud. It hasn't rained a drop in a few months. On the other hand all that heat and dry creates fuel for fires... The Honda salesman and solar installer both asked why we went electric. I've thought about that a lot. I'm not a tree hugger. Any environmental benefit is icing on the cake. I do like the technology and grabbing free power from the sun. But I've finally concluded I just wanted to make a step forward. I don't plan to ever go back to an ICE vehicle nor a hybrid. My next step would be an EV when charge times are under 15 minutes and at that point I wouldn't go back to a PHEV.
A roof replacement as part of the solar install would definitely qualify for the 30% tax credit. If you didn't take it last year, take it this year. Also, in California, our systems do not add to the AV of our homes. So your property taxes should not go up more than the normal amount. 1% AV/yr. Prop 13 is still paying some dividends.
Thanks for the data. Interesting info about the fire effects. Here in Michigan we can get solar installed for about 2.5 cents per watt, including equipment and labor. If you then factor in the 30% tax credit, even here in mid-Michigan with its winter clouds (thanks Lake Michigan), we can get get pay-back times of 6-8 years for a modest sized system. My own off-the-grid solar charging station for my Clarity is in that pay-back time range too.
Hmm, that seems pretty high for 20 panels. What wattage are the panels and what make/model ? Also, what is your total solar kWh capacity ?
The roofers were all booked at the end of 2017 when the solar was to go on the roof. One was good to help out and did 1/2 the roof in 2017. The other half was done this year. I did claim the first half. Not so sure I can claim the second half.
The panels are LG365Q1C-A5 365 watts each. Today they produced 43.42kWh. Back in June we were getting 51kWh per day. Total system is rated at 7.3kWp but the most I've seen is a little under 7.
One other factor to consider in your calculation is that SolarEdge inverters record about 2.5% above actual production. You probably have a second dedicated meter that was installed alongside your street power utility meter—in my state the dedicated solar meter is monitored and reported separately as part of the state rebate we received. That meter records what actually is produced. You might want to add your system to pvoutput.org.
Ha, the LG brand and the higher wattage justifies the price . I have Canadian Solar panels with a SMA string inverter.