I am committed to sustainable living. I have a
separate page devoted to all the efforts we are
taking in that regard. This section of my web site documents my
experience while researching, designing and installing a grid intertied
solar power system in the summer of 2009.
An early decision was to use the new microinverter technology. Instead of the panels being wired
together to create high voltage DC that is sent to a large single
inverter that converts the DC to the AC we use in the home, each panel
has a micro inverter mounted right behind it. The power is converted to
240 Volts AC right there at the panel. This makes the system more
efficient and more flexible. It eliminates the shading issues that can
compromise the performance of DC systems where panels are wired in
series - shading any one panel in the series will compromise the whole
string. Also one can mix and match panels of different capacity
allowing one to grow a system with a blend of panels as you can afford
them. Overall this system has a slightly better cost/performance
More about micro inverters on Wikipedia.
The only disadvantage of installing a grid-tied solar system like this
is that there is no battery bank. So when the utility power fails the
inverters automatically shut down to protect the line workers. So we
will still need to rely on our
Generac automatic propane backup generator (purchased from a local
big box hardware store) during power outages. In recent years we have
lost power for an average of 5 days each year due to 2 heavy snow
storms, Maine winters can be brutal. This cost us several hundred
dollars in propane, so the trade-off of a battery-less system can get
expensive on occasion. But in the long run it is less expensive than
installing and maintaining a battery bank.
Several other factors influenced our decision to go solar now (2009), low
mortgage rates, recent drop in the cost of solar panels, and the
federal tax incentive that allows us to take 30% of the cost of the
system off our federal taxes. (We did not get the credit we expected in
the first year because we are self-employed
more on that here). Note that prices of solar
panels have plummeted since I did this installation!
Maine's electric supply has one of the highest renewable ratios in the
country, in 2009 about 30% of the electricity delivered comes from
renewable sources. In 2020 it is more than double that - mostly
sourced from Canadian hydro.
more about other states renewable energy portfolio here.
Also, here's a site that lists comparative electric rates for US states.
So my next task was to figure out how many panels I would need, and
where to put them all. Go to the
next page to see
what I learned. Also if you want to see a similarly detailed blog about
a ground mounted solar power system that also uses Enphase inverters
like mine - take a look at
Gary Reysa's site: Build It Solar.