Solar Update and Q&A

Many of our friends and family have expressed an interest in solar power but given the expense wanted to let us be the guinea pigs for it. Now that its been 8 months I figure we have some real world experience to share.

Does it Really Work?
From January through June we produced 5680kwh. Typically these months produce 52% of the annual production, so we’re on course to produce 10900kwh this year (a bit above the annual average use for a PSE customer). This is about 10% more than the installer estimated, meaning our system will be even cheaper than we originally predicted this if overproduction continues. So short answer, yes, solar power does work even in rainy Seattle.

Any Problems?
So far not a one. It has dealt with feet of snow and windstorms without issue.

What About Maintenance?
Zero so far, the rain has been keeping them clean and our trees are far enough back that debris hasn’t been an issue.

I’ve also gotten many recurring questions, here’s some common questions and answers about solar power.

Is my roof orientation okay?
A southern facing roof is ideal, but ours is more east/west and we produce only about 5% less than our cousin’s system which is more south facing. I’d avoid solar for heavily shaded roofs and north facing roofs, but otherwise don’t let concerns about the roof get in the way of considering solar power.

Will my HOA Allow Solar?
As long as you own the roof (e.g. not a condo) legally an HOA cannot ban rooftop solar in Washington State (RCW 64.38.055). HOAs can reasonably limit aesthetics (e.g. banning tilt kits) but a homeowner does have the right to install solar power.

What about cloudy days?
When people think of solar they often think of being off-grid, but most residential solar power systems are actually grid tied with net metering. When the system overproduces the power is sent to the grid and you get credits, when it is nighttime or overcast you pull from the grid and use the credits or buy power when the credits are all used.

What about power outages?
Solar power systems actually turn off when the grid power is down to protect the lineworkers from being electrocuted. If you want to use solar power to address outages you’ll need batteries like the Powerwall and an automatic transfer switch.

What About Online Estimators like Project Sunroof?
Project Sunroof is an interesting Google service using satellite data to estimate roof solar potential. It is however just an estimate – it appears to underestimate my production potential by at least 20% and overestimated the cost of my system about $14000 too high. When you get a solar installation quote any reputable dealer will use a Suneye (or similar PV analyzer) to get better data to estimate production.

Knowing Power Use

Every month you get a power bill but chances are you have no idea what most of the devices in your home cost to run. While that might sound nitpicky to understand, by knowing where your power use goes you can make smarter choices about upgrades and appropriate settings to reduce use.

For example in our previous article about beer fridges it turns out a 90s fridge uses so much power you can save hundreds a year by replacing it. The same can be true for old AC units, some set-top boxes, older plasma TVs, etc. Rooting out power hogs can have a huge impact.

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LED Bulb Replacement Calculator

I’m sure you’ve already heard about LED lights, but I’m in awe how often I still see incandescent and halogen bulbs around. There are a few common reasons people give such as color, dimming, and cost – but I think they’re outdated concerns with the latest LED bulbs.

People understandably like the warm glow of incandescent bulbs, however LEDs have come a long way. The Wirecutter says the Cree bulbs “look as good as incandescents” and dim all the way to zero without humming.

I also hear people say they only use their bulbs a few hours in the evening, but when I made a calculator I was surprised to find an LED bulb will often pay for itself in the first year with just an hour of use a day. Not to forget changing out the lights in a living room alone can save hundreds of pounds of CO2 annually.

Check out the calculator below, its preloaded with some average defaults but you can also tweak the numbers to your needs.

Your Beer Fridge is Wasting Your Beer Money

There’s few things more American than keeping an old fridge in the garage stocked with beer. But have you considered how much beer money that fridge wastes?

Take for example a 1990 side-by-side fridge. Running that for a year costs over 500 cans of Kirkland Signature Light Beer. Even a year 2000 top freezer refrigerator costs 260 cans of Kirkland Signature Light Beer.

There’s a few simple answers – consider doing without or getting a new fridge. For example at Best Buy a 115 can beer fridge is $199 and costs just 73 cans of Kirkland Signature Light Beer to run.  A larger 10 cubic foot fridge freezer costs just $299 and costs just 75 cans of beer. In 1-2 years replacing an old beer fridge can pay for itself, leaving you plenty more beer money.

Learn more about your current beer fridge’s operational cost (in dollars) at EnergyStar.

Two Easy Things To Cut Your Home Heating Bill and CO2

Home heating turns out to be a huge impact environmentally, heating a 2000sq foot home in the Seattle area can commonly range from $500-1700/year and 7000-17000lbs of CO2 annually. Needless to say modest improvements in efficiency can have major impacts.

While there’s huge, expensive projects you can undertake to cut these factors, there’s two simple things we did which cut our impact roughly by a quarter.

Below is a picture of our “new” (1980s) home gas use (we’re the blue line). In October things started to cool off here and you’ll notice we were running at the same gas use of an “efficient” neighbor, but since then we did just the two improvements below and now use 26% less natural gas than an “efficient” neighbor.

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Greener Home Heating

Home heating turns out to be an incredibly complex and regional issue – how much heating is needed, the practicality of heat pumps, and grid energy emissions vary significantly in the US. Not to forget your home variables – what services are available, ducting, current system efficiency, etc. Given that keep in mind there’s no one answer that works everywhere.

While home heating a complex and fairly mundane topic it deserves a lot of attention – some back of the napkin math suggests home heating and cooling in America is responsible for at least half a trillion pounds of CO2 annually.

We’re going to look at the three main categories of heating systems – electric resistive heaters, heat pumps, and gas furnaces.

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All About Home Battery Storage

What is Home Battery Storage?

Basically these are battery packs like used in EVs but for your home power. They can be used with or without solar, but the rebates only apply when used with solar.

Will Home Battery storage save me money?

It depends on your utility! For example if your utility charges time-of-use rates you can use the battery to run your house during high rate hours then charge the battery off-peak hours. Also if your utility doesn’t offer solar net metering it allows you to take full advantage of the solar power you generate.

But at least for major Western Washington utility users (PSE, Seattle City Light, and Tacoma Power) these aren’t a concern.

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