We have lived in an off-grid solar home for over two years now. We have twelve PV panels on our roof. It’s a 48 volt system, with a huge bank of AGM batteries, a xantrex inverter and an OutBack Flexmax M80 controller. We have a backup propane generator. All that probably means something to those of you out there who know solar houses – it meant nothing to us two years ago.
When we started planning our home, almost a decade ago, we knew that we would want solar. We were moving to a very sunny place, so why not take advantage of it. We were also a long distance from utilities. Whether it would be off-grid on on-grid was a toss up, depending upon how expensive it would be to hook up to power. It continued to be a toss up until we broke ground for our home. At that point we found out that pulling power, and running water to the location of our house would cost approximately $75,000. Since we knew we wanted to have solar even if we pulled power to our house (and had already sunk $12,000 into the PV panels) and since that would cost ~$35,000 by itself, it became pretty clear to us that we would be off grid and drill a well. So the solar, with the backup generator, was ~$40,000 and the well was ~$15,000. Big ouch, but a lot cheaper than being on-grid with county water. Plus no monthly fee for either.
We were so ignorant and naïve about solar energy. And, unfortunately, our installer (although very knowledgeable about installing systems) didn’t take the time to explain in kindergarten (or preschool) terms what living solar entailed, or to ask us what our expectations were. When we first met with him, I had compiled a year’s worth of electricity bills from our on-grid house in the city. I told him that I had brought them, but he waved them away and said they were meaningless. What?? Over time I have learned that he may have been right, but at that time I was astounded. That was how we lived – didn’t he need to see that usage to determine what our needs would be? He looked at the tentative plans for our new home and when asked, he said that we would probably need 10 PV panels, based on the size of the home, not on our current usage. So we bought 12. We didn’t want to be underpowered. Other than that he made a number of comments to the draftsman about design (who attended the meeting with us) that sounded pretty expensive. He said we would just live “normally” and have “regular” appliances (albeit energy star), including a microwave. No need for a propane refrigerators like two of our neighbors have. Whew! We asked about whether we should have the panels on the roof, or on a tower. He told us how much his tower cost ($15,000 extra – outrageous!) and that answered the question for us, they would be on the roof (more on that later). I also didn’t want our beautiful scenic view interrupted by a big tower of panels.
Jump forward to the building process. The installer found a great deal on a slightly used 48 volt inverter, so we said yes, despite the cost of the doubled size of the battery bank (ka-ching!). As it turns out it’s a good thing we have such a robust system because our expectations were that we could “live normally” just like he had told us at the first meeting. And, we would feel like “failures” if the backup generator had to come on (in addition to not wanting to pay the additional cost of propane). Are we living normally? Not by our previous definition of normal. But, we are establishing, slowly and sometimes painfully, a new definition of normal.
Some things we found out in the first few weeks.
· The motorhome refrigerator uses a
LOT of energy when running on electricity.
We used to keep the motorhome plugged in at all times with the fridge on when we were home, but we don’t do that anymore.
We empty the fridge when we get home from our trips and turn it off.
· Our old non-energy star chest freezer was an energy hog. So we got rid of it, and eventually bought a small energy star chest freezer that is very energy efficient.
· Hair dryers are major energy hogs, so I retired my old 1600 watt dryer, and purchased a 250 watt unit with a roll brush on the end that actually does a better job on my fine, thin, wavy hair. Many times I don’t use a dryer – who cares out here if I’m frizzy?
· Old style CRT televisions are energy hogs, even “energy star” rated ones. No more leaving the TV on as “background noise” while in the house. Eventually, when we have some throw away money (or the old ones break) they will be replaced by energy efficient LCD TVs (but not all LCD TVs are energy efficient!). Desktop computers, even with flat panel LCD displays can also use a lot of energy. So don’t just leave it on all the time – turn it off or to hibernate. Laptops don’t use much energy at all.
· Incandescent lights are energy hogs. We have now replaced all our incandescent bulbs with compact florescent bulbs – that was an expensive move, but worth it.
· Energy star refrigerators still use a lot of energy.
· Gas ovens had a 10 amp heater coil that stays on all the time in the broil setting (but not in the oven setting – it only comes on to ignite the burners in the oven setting). Why??
And then there were other problems. We have a monitor in our laundry room that shows us how much we are charging or using at any one time. It also tracks the battery discharge percentage, amp hours used, etc. We became obsessed – looking at that darned thing all the time. How much were we using, how much were we charging. Why aren’t we charging when it is full sun? Why is the generator coming on, or not coming on given what is on the monitor? We were also told at the time the installers were finished that the panels were at the right angle for year round use (even though we have adjustable brackets). We were so stupid – we didn’t look at them and say “huh? they are set all the way down.” So as Fall progressed and we were charging less and less, we were scratching our heads in confusion. Then the generator needed a new battery, and since it was under warranty, one of the installers came out. His comment was “you need to set the panels as high as they will go at this time of year (start of winter).” We looked, and after our initial anger at how they were set (full summer low) we raised them to as high as they would go on the brackets, and low and behold, we began charging like gang busters! Then we noticed that after a discharge down to ~70%, we would sometimes not charge to full, despite several fully sunny days. We called the installer, and he said maybe the Outback controller needs to be replaced, so sent someone out (100 miles) to do so. Better, but still the same problem. So we called again, and the installer gave us some “song and dance” about the reasons why it was happening, but it’s hard to explain something to someone 100 miles away. So my wonderful husband contacted via email the manufacturer of the Outback, and got a much better response. When we told him what our system was, his response was that they had identified that the Outback had some communication problems with the xantrex inverter, and were working on a solution. Meanwhile he told us a work around until his company was able to program that solution. Two Outback units later, and we have version 2.0000 and it works fine (they mistakenly sent us version 1.95000 first, which worked better, but wasn’t a full fix). They are a wonderful company to work with and we highly recommend their product!
So, now it has been two years - and are we living solar? Mostly. We got lazy this year and decided to leave the panels all the way up in what we call the winter position (although it isn’t quite high enough to really be considered winter, actually spring/fall) for the summer and see how it worked. We though, “longer days, more sun, no furnace” – it will probably be ok. Well, it was mostly ok. What we didn’t count on was a robust monsoon season this year. That means we had lots of cloudy afternoons, and afternoons are when you get your most efficient charging. With all the storms, the generator had to come on a few times, but it wasn’t enough to outweigh the inconvenience of having to change the panel height twice a year. All in all, I think our experiment worked, and we will most likely leave the panels in the high position. We think about whether it is sunny or cloudy when we plan meals, especially in the winter – if we have lots of sun and the batteries are reading “full” we use lots of our electric appliances. Why use a gas oven when the little electric oven is “free” or the stove top to cook rice when the electric rice cooker is “free.” Might as well “use” the sun when it is out. If it has been cloudy/rainy/snowy, and our batteries are heading down, we use those appliances more sparingly. In the winter our small south-facing sun room gets toasty – so toasty that we open the door between the sun room and the house and the let that warmth heat our great room. So we have passive solar too. We bought a small corner fan for the door, and it helps to pull that warmth into the house. Doing that saves us lots of propane.
One problem we have encountered that is a potentially dangerous nuisance, is snow on the panels. You don’t get any charge when the panels are blocked. There is no easy way to clean snow from the panels. Once or twice each winter we have lived here my husband has to get on the ladder and onto the very snowy and potentially slick roof (even though it is almost flat) in the freezing cold to scrape the panels. That isn’t fun. It’s harder, and a lot more dangerous, than shoveling a sidewalk. But if the snow falls right before an “arctic express” freeze, we know the panels won’t melt, sometimes for up to a week. That would be expensive, living off generator charges for that long. Our “normal” snow storms are usually followed by sunny days in the 30’s, which means that by late afternoon they are clear. Snow on the panels makes us wish we had put the panels on a short tower, in which case a roof scraper used at ground level would easily clean them off. Oh well, hind sight is so clear.
I’ve probably forgotten a few issues, but that is enough!
Are we glad we have solar? Yes. Would we do it again? Yes. Was it easy? Not really, and we were very motivated.