Using solar power (PV cells) has been around for about 40 years now. For those of you who have taken the plunge - especially those of you who have designed and built your house from the ground up, what are your regrets? The things when you say "I wish I had done xyz!". I am looking for really practical things like "I wish I had put more/fewer outlets in the house" or I wish I had used more/fewer propane appliances. I would like you to share your "mistakes" with the rest of the world so that we don't have to make the same ones - we can make our own new ones ;)
So I can partially respond to this post. I did not so much build a solar powered house as I took maximum advantage of southern exposure for heating the house in winter. The house is a two level plus basement. We have a great room that is a double height (two story) room. That room has a lot of natural light that comes in and was built to have very good eastern and southern exposure. In the winter months, the low angle of the light reaches much of the house. On a sunny day, the light naturally streaming in can raise the temperature quite a lot, and that heat is allowed to rise upstairs and helps heat the bedrooms (it is a very open design).
So that part is the solar part. Of course there are things I would have liked better such as better windows, I did not go with 2x6 studs, but that does not seem to have mattered much as I put in some pretty good insulation. There was one error in construction that could not be fixed. I developed the basic idea for the house myself, but I had an architect "correct" my mistakes. This was obviously necessary as I knew I had not thought of everything. He gave me back about 85% the same design and it was much better. I gave my plans to my contractor who had to convert the measurements into another blueprint in order to get things like parts list, etc. While converting the first set of plans to the second set, the person actually doing the drafting (son of the contractor as it turned out) accidentally snapped the back wall of the house as being a zero width line instead of a 3.5 inch 2x4. This means that the entire house was narrow by 3.5 inches. Normally this is trivial, but the error was not caught until after the basement had been poured, the walls and floors went up and it became evident that a central hallway was a bit more narrow that it was supposed to be. In the end, it really does not matter much, but it would have been nice to get the measurements correct.
Other than that I have no real complaints. We could have put in better and more expensive everything, but then we would have paid a very pretty penny for the house. Building your own house is a challenge. I guess my best advice is to plan thoroughly and have someone double check the plans.
My biggest regret was commiting to solar panels on the roof and not putting them on the ground. I was influenced by a lot of the 1970's solar design books mostly built in more southern climes. I ended up having to build a cupola into the attic to make cleaning them off easy in the winter as it snows here... a lot.
Since the house was built as a cube for efficiency (3 floors, 430ft each) the roof does not have a large footprint. When the price of panels dropped I did not have the room on the roof to take advantage of a much larger array. The passive solar aspects work great the propane dryer and hot water heater and stove were the right decision at the time but we hooked up to the grid eventually to replace the propane back up generator. Next house which is in the design stage will have a net metered array with battery backup and be an all electric house... Ontario's grid is mostly nuclear and Hydro electric so all electric makes sense. If I lived where the grid was mostly coal or natural gas the decisions would be different... So, ground array, Use the grid if its available, all electric if your utility is not all coal based.
By dumb luck we didn't make too many mistakes in the design & construction phase. Here's the changes we did make.....
1- Initially the solar panels were on the roof. Hey, everybody puts them on the roof, right? For our situation, it was a mistake. The ohia trees around us cause a lot of dark debris to coat the panels, thus we have to clean them regularly. Up on the roof it became a nightmare. So we moved to a ground mount and made sure that they would be easy for us to clean once a month. Much better.
2- When we first put up the solar panels, we followed the advice and pictures in the books. We discovered that it wasn't a good solution for our location in Hawaii. First of all, we discovered that we get mostly sunny mornings and overcast afternoons. So we changed the direction of the panels to optimize the pre-noon sun. We added 4 panels pointing at the 9 am morning sun, and 4 pointing at the 2 pm afternoon sun. 24 panels are ground mounted pointing at 11-noon sun. (Our panels are the old unisolar 65 watt panels, that's why we have so many.) This method works far better for us.
3- We have a DC freezer and initially had it the kitchen. The house is wired for AC, meaning that we had to have a converter to change the AC to DC in order to run the freezer. You lose power every time you convert from AC to DC, and visa versa. We decided to move the freezer closer to the battery bank (out in the utility shed only a few steps from the house) and run it on direct DC there. At first I was worried that it would be real convenient, but that didn't prove to be the case. We are totally fine with the freezer out in the utility shed.
I wouldn't call these regrets. We just tweaked our system to make things better.
It's never too late to start! I retired to homestead on the slopes of Mauna Loa, an active volcano. I relate snippets of my endeavor on my blog : www.kaufarmer.blogspot.com
Hi Tom; I got my first solar panel in 1983... so I guess I've been off grid almost 40 years.
My system has gone thru many changes over the years ,including moving them to a new home.
We have solar and micro hydro for power. Propane fed backup generator.
We use propane for refrigeration, cooking , hot water,the genset and 3 small heaters.
Our panels are pole mounted up high .They can be, but never are hand turned. I have never cleaned them. Dust washes off with rain. Most the time the snow slides off quickly.
If I was to upgrade , it would be to a shorter pole mounted, automatic tracking system.
Not many regrets but I would do a few things different.
First, I wish I had gone 24 volt over 12. Nowadays even 48 volt is common. Power transmission is so much easier with higher voltage.
Second, refrigeration/freezing , I have used propane refrigerators (and still do) the whole time. Starting with the bear resistant old Servel models thru the plastic dometics.
And finally to a 17' Amish built Diamond. It compares in quality and size to any modern electric fridge. Sips propane compared to the old ones.
Freezers are a different story. We have had a 110 vt ,1970's chest freezer for 35 years. (The power sucker) Have had to keep it at various neighbors house's. At a cost of $100 a year... over $3000 up in smoke.
It has not even arrived yet, but I just purchased a 12 vt Sundanzer chest freezer. I will give it a 600 watt stand alone system in the barn. I wish I had done this 20 years ago...
After I have had a chance to see just how well this freezer performs , I will be seriously looking at the 12 vt sundanzer refrigerators. Super insulated , full size, sips 12 vt power or they have them in 110 vt as well.
With one of those I could cut my propane usage back...
Third, Inverter's should be pure sine wave only. I believe in having more than one. That way when (not if) one breaks you still have a working system.
Your whole home should be fully wired for 110. Outlets everywhere , you will want them.
In my case I also still have a 12 volt string with a few lights that is in place and used. We shut our 110 power off at night.
Last is the heart of the system . BATTERY'S... What kind ? How big ? What brand ?
I wish there was a good answer for those questions.
Lithium ion battery's are now available for off grid use, but the cost is still out of reach of Montana poor folk.
Nickle iron , nickle cadmium, and the long standing lead acid ???
Battery technology is improving but who knows what to invest in? Personally I currenly use AGM lead acid.
Will I in ten years? I hope there is a better choice by then.
One thing I wish I'd done was include a couple of extra wires in the underground pipes coming from the solar component shed to the house, not connected up at either end, so if in the future we wanted to add a circuit or a connection, the wire would already be there.
I did not know how glad I would be that we down-sized all the appliances, and put them all on power strips appropriate to their wattage, (not all power strips work on 1500 watt appliances) to be turned off when not in use, so the ghost power that a lot of appliances use (printers, washing machines) isn't sucking small amounts of power 24/7.
And I agree with David, the panels are much easier to care for on the ground, and add to, especially when the hornets put a nest underneath.
Don't fall for the My-Place-Is-Special, It-Won't-Happen-Here Syndrome.
Diego Footer on Permaculture Based Homesteads - from the Eat Your Dirt Summit