Getting paid for solar

[Neal]

I'm in Casa Grande until April and last year electricity was a bit expensive. I didn't use solar as there was discussion back then about electricity being cheap, not the case here. This year I'm using my tools via Magnum ME-BMK and Victron stack to use solar from 9 AM until 4:30 PM. This allows all inverter loads including battery charging to be handled by solar while that big yellow orb in the sky is doing the work. With 10 panels on the roof (1800W) it's almost a crime not to use solar. It's been working great for a week now, SOC has not dropped below 100%. I actually wanted to switch to battery at 7 AM and let solar do the recharge work but I did something that triggered LBCO one day (11.0V set) and haven't retried yet. I had hoped to cover some of the morning's more expensive demands (coffee, microwave, etc.) via 900 aH of battery muscle.

With that said, it's a shame I can't be credited for electricity I could push back into the system. It could probably pay for one's stay to help supply the electrical grid from RV's with solar. Not using solar when solar panels are available is unfortunate. Hopefully this would change someday for electric companies to take help from those with solar.

 

[Retired]

I read about a few skoolie conversions where they used 2 Prius battery packs to store solar. The batteries had the capability to store all the power the panels generated.

Its better to store and use the power you generate vs selling back to the utility .

My home electricity provider is a coop. I pay 10.5 cents a KW, no peak useage.

If I were to sell back to them, I would only be paid what they pay for raw electricty. Currently thats 2.6 cents KW.

Can you increase your battery capacity?

 

[Gronk]

When I was in Casa Grande last spring my last electric bill (for only THREE weeks) was $155!! Temperature was over 100 degrees every day with bright sunshine. Even with two ACs running it would still get to 80 degrees in my trailer.

 

[Kevin D Pem]

When I was in Casa Grande last spring my last electric bill (for only THREE weeks) was $155!! Temperature was over 100 degrees every day with bright sunshine. Even with two ACs running it would still get to 80 degrees in my trailer.

On occasion I is nice to see how others live. When I did stay two months in an RV park last summer, my electric was 32 dollars a month. And no I wasn't using my solar. Details: 105 degrees outside 95 in. And counting the days when I could return to the high county.

 

[Neal]

One thing I need to figure out and probably could if I got my lazy arse out to the meter to take meter readings is what I'm really saving by using solar. I should take readings on a day without solar, readings on a day with solar but the real question is when days are marginal such as clouds or I use a high demand device such as convection oven, broiler, microwave and don't get back to fully charged (100% SOC) what is the cost for the high amp charge hit against shore power? For example, it probably takes little power to maintain a charged state but if I only get to 90% SOC and I draw max amps to charge, what is that costing me?

I'm showing about 6 kWh/day of solar intake so that's obviously 6 kWh I'm not paying for.

In the end I won't have a baseline to compare to in order to realize savings but at least I'm putting all this hard earned solar to use. Crime not to capture solar in AZ.

 

[Kevin D Pem]

@Neal really solar is a way of life. No Way it will keep up with unmodified habits.

 

[Retired]

I pay 10.5 Cents a KWH, so if you are generating 6KW per hour, then you are saving 63 cents an hour.

That doesnt seem right.

Year round my home averages 30KWH per day electricity use. Some cold winter days its 70 KWH+, some mild days its less than 10 KWH.

 

[Neal]

I googled casa grande and it’s around 11.6 cents per kWh. So it seems futile but I’m sure the campground is charging much more. Probably not worth doing this which was my same conclusion last year and didn’t.

 

[Retired]

If I sell electricity back to my provider, they pay 2.6 cents KWH. Thats what they pay for raw electricity. I have no peak usage, its all the same price 24/7.

I use so little at home, solar isnt a good investment for me unless I needed it for outages, then I would need a Tesla battery wall as well.. All my utilities are underground and the substation is less than 1 mile away.

You would do better figuring out a way to shade your coach.

 

[Gronk]

I googled casa grande and it’s around 11.6 cents per kWh. So it seems futile but I’m sure the campground is charging much more..

Neal, the campground I was in there has the price at .18/kw for a winter rate and .20/kw summer. Naturally, the last bill I had was when they switched from winter to summer rates.

 

[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.