I contributed to a Kickstarter campaign for Legion Solar, buying panels and a micro inverter which could deliver 2kw of power.
The system is not designed to replace my electrical needs with solar, rather it is a learning experience and a way to offset some of the very expensive electricity we have in Hawaii.
My electric bill for last month (31 days total) was $110.47 and I used 375kwh or about $3.56 per day. I use very little power but our rate is higher than most places in the U.S. In calculations people always quote just the kilowatt hour price of electricity but I think it should be quoted as a total cost which includes all taxes and so on. After all, to get that electricity you have to pay fees and taxes so look at the total cost of the service, not one part.
So on a very sunny day with many hours of sunlight minus inefficiencies, I will not be able to replace the electric company with the solar system I bought. However, that 2kw system only cost $3200. What I hope to do is take some electric usage away from the utility and some of that will be due to the solar panels.
One of the biggest users of electricity in my house is the water heater. Electric water heaters are generally 220 volt. They heat water with a coil and when the water reaches the set temperature, a thermostat turns off the power. As water is used or if the water in the tank sits and loses heat to the environment, the thermostat will kick back in and heat water again. The system will keep the water hot in case you want it, whether you are on vacation or not. I turn my water heater off when I leave for more than a couple days. Some people use a timer on their water heater to shut it down during long periods of disuse. There are even ways to shut down a water heater (or other appliances) remotely while you are traveling.
If you have a gas or propane water heater you may have the same cycling, plus a small amount of standby usage due to a pilot light.
With out high cost of electric, I decided to invest in a tankless propane heater for water. This unit is an on-demand unit. It uses no propane until water begins to flow, then quickly energizes and heats the water. Within seconds I have hot water, but the minute the water flow stops, the heating stops. There is no tank, so no holding of hot water. One plus with this system is there is a remote thermostat which I can install in the hallway upstairs. That allows me to adjust the water temperature as I wish. If I want to use the dishwasher, I can crank the heat up if I want. I just press an up arrow button a few times.
If I want to reduce the cost of heating water, whether using electricity or propane in my case or natural gas elsewhere, I could preheat the water before the water heater or tankless systems gets it. Underground supplied water is perhaps 37 to 77 degrees or so depending whether you live in the north or south and time of year. In Hawaii we have a temperate climate and in fact, my water lines are not buried at all; lying above ground. The water pipe is black so it could actually absorb more solar heat if it was in the sun (which it is not). So I don’t use as much energy to bring ground water up in temperature as others might have to.
Another way I have been cutting back on electricity use is by switching to LED bulbs. Lately I have gotten great deals on CFL and LED bulbs. I prefer LEDs because they do not contain mercury like the CFLs do. Also, LEDs and CFLs don’t generate the heat that incandescent bulbs do. This can also reduce cooling costs for those who live in areas with high heat already. I once had halogen lights in the dining room and even though they were 10 or more feet from me, I could feel the heat. The LEDs I replaced them with are cool to the touch.
So if I am not going to use the solar panels to heat water, what then?
The system I am going to install will not start out with batteries, thus there is a lower cost. Batteries store solar panel energy and can be used during cloudy days or at night. Batteries are expensive and a maintenance issue. My system will only supply electricity when the sun is shining. What good is that you ask? In many places electric companies will allow you to connect your system to their grid and you actually become a supplier of extra power to the company. They may pay you or offset your bill, etc. When you produce more power than you use, the extra heads their way. There are a number of hoops and inspections and agreements you must agree to.
If you don’t use battery storage then your solar usage is limited to the electricity you produce during the day and then only sunny days. You will produce less electricity during cloudy days and none at night.
So I have a few things I’m looking at. I have some irrigation systems which can operate during the day, however it is best not to water during the day as sunlight evaporates the water. However I also have multiple water tanks and moving water from the lower tank to the three up top on the property requires power. Although pumps to move water uphill can require a lot of power, a smaller pump will take less electricity and longer to move the water. This would allow me to move water at no cost.
I also operate coffee processing equipment during the day. It does not require much power as I currently use an extension cord to power the equipment. This is a perfect application for solar without batteries because I do all the processing during the day.
I started looking at other things I use during the day and what I could hook to the solar panels. I charge batteries often, use an air compressor, have various lights on and so on. I also use the microwave and have telephones, the computer and modems and so on. Some of these are used only during the day and some are used both daytime and nigh time.
A typical example of an appliance used only during the day here is a window air conditioner. If it is not sunny, it will not be very hot, thus no need to cool things. I sometimes use a AC unit to cool down a room for the dogs or to remove a bit of humidity, so it might be a candidate for solar.
One thing which is useful is a transfer switch. These can switch electric equipment from one source to another if power fails. The most common usage is if the power company goes down, people automatically start up a generator and witch their electricity supply from the dark utility to their generator power. This can also be done to switch certain circuits from solar to the power company if there is a loss of sunlight or at night. The switch-over may be transparent to the devices if the right transfer switch is used.
So I can have lights and equipment hooked up to a circuit controlled by the switch and if there is no sun, the switch automatically switches to the power company and I start paying for the power I use.
In some net metered areas, all the electricity you generate with your solar panels can be routed to the power company and they offset what you generated vrs what you used. Since I may not net meter, I expect to initially use whatever power I generate locally.
So I have started a list of items that I only use during the day, items that have been used at various times but could be converted to daytime only use (like battery charging) and things which cannot be used on solar (nightlights because they are not not daylights) and things like the drier which is a big energy hog.
I also am looking at each item to see if they will operate smoothly with a transfer switch.
As I said, this is an experiment that I have undertaken. I know how solar works but wanted to get deeper into inefficiencies and ways to make it work for me.
One plus for the system I am getting is that it is customer installable. Their roof system eliminates the cost and problems involved with drilling through the roof to mount traditional cells. I have a large area next to the house which can be utilized for ground mounted cells, thus I don’t need to get on the roof at all. I also can adjust the panels easily if I decide to follow the sun during the seasons rather than pick an intermediate solar angle to the sun. Roofs are useful when you need to have a better view of the sky. I have that already at ground level. Although a ground installed system might be a security or theft issue, I have guard dogs, cameras and a security system to alert if a panel is disconnected.
I think it will be exciting to get the system installed and see how this works out.
I will keep you up to date on how this goes, but delivery of the panels is not until 2017.