I live in the Boston area and don't have a lot of south facing roof area, so solar electric (PV) was basically not going to work. i have a sunporch with limited south facing exposure which gets a little overshadowed in the winter by a nearby house.
My regular hot water heating makes me very frustrated in the summer. We don't have a natural gas line, so the oil fired furnace comes on every couple hours to keep a 'tankless coil' heated for our use. There's nothing like hearing the furnace come on when you're in the basement on a July day that's 90 deg F outside! Also, these tankless coil things have definite lives and mine was getting aged - beginning to let water leak into the furnace. I looked into better options...such as an 'indirect fired storage tank' which your furnace would heat up and then the water stays super insulated and warm until you need it. This saves fuel and money. A good indirect tank was going to cost me about $2000. My current oil tankless coil system was also not able to supply a large volume when a bath or a lot of hot water was needed. You had to get really good at letting the tub with with a SLOW stream of hot water so the tankless coil could instantaneously produce water in the summer (though in the winter, it was okay, because the furnace is hot all the time). During the summer though, my oil person said I was using 1-2 gallons of oil a day -- even if I used no water, just to keep the tankless coil hot! By my calculations the oil furnace was costing me $250-400 for the months the furnace wasn't house-heating, at about $2/gallon.
Over the years I'd been thinking about what to do to get some sort of solar-powered system in there. I managed to get my mower running off solar PV, but that is a minor thing.
I went to a local solar PV place (Sunbug Solar) and asked about this and they directed me to New England Solar Hot Water, for 'the other solar' - hot water. Right on the website was a note that pointed out that (as of now, mid 2017) federal and local MA rebates and tax credits would pay for about 75% of the cost of the system - and that the final cost for me would be about $2,000.
NESHW came out (an Architect or system appropriateness person) will come to see if it can work for your site. We discussed several ideas, but in the end I went with a not-too visible installation of 25 evacuated solar tubes on the porch roof. Tubes are a bit more efficient and a bit more expensive, so most installations will have solar panel looking things, if you have the room. The tubes just (and I mean by a couple milimeters!) fit between existing obstacles on the roof. The team of 3 installers did a great job getting it to fit and all were very glad the architect/sizing work was done accurately.
My system is a drainback system, meaning a pump sends the fluid that picks up the heat from the roof up only when conditions make sense to do so. It's a simple way to do things, but should be very reliable and frost-free, which is important in the north. The fluid is a nontoxic liquid that cycles through a tank down below and heats the water that is used in the house. The tank itself can have a backup electric coil (you'll need your electrician to connect that to your house wiring) and turns out to be a super insulated tank - just the sort I was going to pay $2,000 for if I'd hooked it up solely to my oil furnace.
To my surprise and pleasure, quite a few of the system parts were made here in the USA and even in Massachusetts! In my case, the tubes and the tank were both made in MA.
My system doesn't payback as quickly as most SHW systems (I think it's 8 years until the heat in my water is "free"), but in simplistic terms, I was looking at a $2000 upgrade and would have been still using oil to heat during the summer. For about the same money, I can turn off the oil furnace entirely during the summer/sun months. In the 4 or 5 summery months, I've only noticed the electric coil in the tank come on a total of twice for minutes. NESHW's in-house plumber set up valves so that I can 'switch over' to furnace backup as those short winter days arrive. Oil is cheaper than electric, in general. Also, as your oil furnace person will gleefully tell you, heating water in your oil furnace in the winter is 'like getting something for nothin' ", since your furnace is hot keeping your house warm. Of course, you are paying, but you do piggyback on the furnace heat a bit.
One more thing, NESHW offered 'monitoring' as an option that would cost me a bit more. I decided, being a tech/reporting/geeky sort of person that I wanted to know how my system was doing. What the extra monitoring money paid for was connecting the solar hot water controller to a logging system and out to the internet via my home's existing router and cable modem. I can check the system at any time and from any place with an internet connection. In some ways, the reporting and monitoring you can do with the monitoring option is the best way to get to know your system and to keep an eye on it. I instantly liked it. I check the system still pretty regularly with my PC, Iphone and tablet. If you're the kind of person who wants to see how much heat you've created and how the system is doing after you take a shower or what the pump is up to, the monitoring is essential.
Caveat Emptor/Full Disclosure: After I had my system installed, I liked and used the system monitoring so much that I have started helping NESHW with the monitoring and reporting - I set up and maintain the monitoring reporting. You can certainly take my review of NESHW with a grain of salt, but hopefully you can find the information I've provided useful, particularly if your site has similarities to mine. I haven't been asked to provide a review, and haven't been compensated.
