Somerville Solar Survey

[mzrowan.livejournal.com]

Somerville is surveying residents to gauge interest in city-sponsored/organized solar programs: http://www.somervillema.gov/alerts/survey-residential-solar-program-interest

The survey will be open until Feb 21 and is open to both owners and renters.

Comments

[bobobb.livejournal.com]

Neat, thanks for posting this. I've always been intrigued by solar, but terrified of damaging my roof. Anyone know what the risks associated with that are?

[somerfriend.livejournal.com]

A structural engineer must sign off on the project beforehand and may recommend additional bracing or something like that, though usually not. The installers know what to do to avoid leaks.

[somerfriend.livejournal.com]

I gather from taking the survey that Somerville is going to bid to become a Solarize Mass town. A Mass CEC program that is a group discounted buying program. According to Mass CEC website, applications for Solarize Mass 2015 were due from towns in October 2014, so unless Somerville applied in secret or the website is not up to date, I guess 2016 would be the earliest year.

[mem-winterhill.livejournal.com]

I filled it out as soon as I heard. I would love more info on it. I already have solar hot water, which cut my gas usage and bill by ~15%. Been pleased with it.

And now thinking of blizzardageddon, I would love to have my own little power factory on my roof to be able to kick over the furnace if the power goes out.

[somerfriend.livejournal.com]

Do you have gas heat? Is that 15% off usage outside of winter?

[mem-winterhill.livejournal.com]

Yeah, I have gas heat, so that was in winter months, compared to similar previous winter months. And if the heat wasn't on (like late spring/early fall). Things that were about the same avg. temp and therms and length of billing cycle. It's a rough estimate because of several variables.

I also work from home so I do specific things like run the dishwasher and laundry when it's sunny, take showers after a couple of hours of sun, etc.

[somerfriend.livejournal.com]

Not quite following, do you have solar for heating of domestic hot water or heating of your house's temperature (more rare)?

[mem-winterhill.livejournal.com]

The solar hot water is for the showers, dishwasher, laundry. Not the whole house. The rest of the house is a gas boiler. And I have a gas kitchen stove.

So it's hard to figure out exactly what was the benefit from the solar panel vs the other gas use. You can get data that varies in amount of billing days, it varies across temperature over the month, and sometimes I do more laundry or dishes, or cooking, or less. I can't account for all the variables.

What I could do was look at similar months, like this: http://screencast.com/t/ozfLSqaG1qVT And it was years ago now, so I don't have that data to show in the National Grid interface. And over time we were doing other things, like better insulation, better windows, so it's really hard to assess the specific benefit of the solar hot water piece.

[pywaket.livejournal.com]

One thing to be aware of is that most solar electric installations on houses these days are what is called "grid-inertia", which basically means they have no batteries. One of the downsides of them is that they are designed to shut themselves down when they don't have any incoming feed from the utility. They do this because they use the utility to synchronize the inverters, and also, to keep them from backfeeding into your local grid when the main grid is down. This is called "islanding", and is generally considered to be a Bad Thing.

http://en.wikipedia.org/wiki/Islanding explains this pretty well.
Also see http://en.wikipedia.org/wiki/Grid-connected_photovoltaic_power_system