Getting paid for solar

[Kevin D Pem]

The real savings are for off grid. Before I went solar I was putting a gallon of gas through the genny. Monthly fuel bill came out to 120 a month. Now It's 0

 

[Calsun]

My home solar array generates 3,597 kW that gets fed into the power grid. The surplus is bought by the local utility at a fixed rate of less than 3 cents a kWh and then they sold the power to other customers for anywhere from 14 cents to 38 cents per kWh. The utility makes the profit with no investment in the equipment to produce that power. I am in effect subsidizing other customers who pay lower rates without capital surcharges as with the billions they have been hit for the nuclear power plants before they were built, while they were operating, and still paying now that they have been shut down.

 

[RKins]

@Calsun that sucks. So why sell it back to them?

 

[Neal]

I just got charged for my electric usage at Palm Creek. For approximately 48 days it was $176, that comes out to around $3.60/day which isn't bad considering their premium site rate for this amount of time is around $33/day. Still very affordable for long term camping. I personally don't care for the area and don't see myself returning for a long time. Not my cup of tea.

 

[Rich W.]

If I stay in a park that charges for elecricity, I wont plug in unless my solar isn't keeping up. The solar panels are just a battery charger (so no way to feed the grid) so it is essential to run off the inverter/battery bank alone to make a difference. For most this precludes the use of air conditioners which is the biggest demand, and you can’t run an air conditioner off your OE inverter/battery bank/electrical system. Even of you have a 3kw inverter, the systems arent wired from the factory to use an ac on the inverter because the battery bank isn't sufficient. You also wont make much progress with a bigger inverter and a LiFePO4 replacement battery bank.

Post# 2 touches on the solution. I have used Nissan Leaf (Li-ion) modules successfully in a system that will run one air conditioner, but its the same idea. You need a minimum of about 20kwh of storage to run an ac from late afternoon to morning, and about 3kw inverter power, and enough solar to keep up with demand during the day so you are near 100% SOC when the sun goes down. Lofty goals and a big investment, but it can be done.

I don’t know about Prius batteries, but a current Leaf battery is over 60kwh (previous gen was just over 40kwh) so you only need about 1/3 of the modules - 2/3 is ideal. But when you pencil all this out, especially if you are paying for system design and labor, it would be hard (impossible) to justify as a cost savings measure. As a hobby and for the pleasure of boondocking and running the ac without the genny it makes sense (sort of) but the quiet diesel generators aren’t much louder than an ac unit.

While I‘m a fan of big inverters and big Li-ion battery banks, Im getting by just fine these days in my current rig with 1575w of solar and my factory bank of 6 LA batteries, but of course no way to run air conditioning from solar/batteries. Depending on how things develop I might go back to a more exotic system when my batteries age out. This would include the use of Nissan Leaf batteries again (min 20kwh, but probably more) and a 6-8kw 48v inverter. I can do this for under $6000 since the solar panels and controllers are already in place, but paying to have a system like this designed and installed would stop me dead in my tracks.

 

[Joe Hogan]

When we installed Solar, 1500W and 600 amp LiFeO4 batteries the front A/C was wired to run off the upgraded 3000 watt invertor. The A/C, refrigerator and incidental loads will run for 2-3 hours but outruns the solar/battery. On a hot day, 98-100F, you barely notice the A/C is on, stays in the 80's inside.
Need generator to top up battery bank before night fall without any outside hookups.

 

[Rich W.]

When we installed Solar, 1500W and 600 amp LiFeO4 batteries the front A/C was wired to run off the upgraded 3000 watt invertor. The A/C, refrigerator and incidental loads will run for 2-3 hours but outruns the solar/battery. On a hot day, 98-100F, you barely notice the A/C is on, stays in the 80's inside.
Need generator to top up battery bank before night fall without any outside hookups.

That all sounds exactly right. Obviously if you bumped up your battery bank(s) you could run the ac longer but it becomes a matter of space for batteries and of course cost. On my Bay Star I could run the AC until about midnight with the Leaf batteries. It was a an elaborate and expensive system and in the summer in the South, it still wasn't sufficient. It was nice for shorter stops during the day when we wanted air conditioning but didnt want to run the generator. These days I just stay out of the South during the summer.