Switching To Solar Power — Six Months Later

ThinSkin writes "Slashdot readers may remember an article regarding ExtremeTech's Loyd Case's experiences with solar power for the home after one month of usage. During that time six months ago, it sure seemed like a great deal, but the tables have turned significantly once winter approached. While it's no surprise solar power generation is expected to dwindle during the winter, Loyd compares solar power data of the last six months to determine if solar power is still worth the time and money."

Comments

$400 a month?

[Gothmolly]

Who the hell uses that much electric power?

Re:$400 a month?

[je ne sais quoi]

Look at the kWh, he's using 1,635kWh per month. While it is high, it's not surprising if his house is especially large and he has a heat-pump. Those things are notoriously inefficient if the temperature drops below 40 degrees F. It getting that cold should be rare in silicon valley, but it does happen.

What I found interesting was that, while December was bad for solar power, he says:

My total power consumption cost for the last six months is $389.39--less than my utility bill for January, 2008.

Basically, his solar power does what it's supposed to more often than not. But then again, we've always known that about solar power, the big problem with solar is the large up-front capital cost of installing it.

(Or other strange things, like my mother just moved into a retirement community and her housing rules say solar panels are not allowed because they're unsightly, but directTV antennas and satellite dishes are just fine. One must have priorities I suppose. Television is obviously more important than renewable energy.)

Re:$400 a month?

[SBrach]

Anyone in the southwest running a 3-6 ton heatpump in the summer when it is over 100F and the winter when it is below 40F. My house is 1400 sq. ft. and even though I have one of the cheapest electricity rates in the country (APS combined advantage 7am-12pm)I still pay $250-350/mo. during the summer. So far my bills for Nov. and Dec. have only been around $150/mo but I also have a load controller on my house which many people say cuts their bills in half. Basically I set a maximum demand limit in kW's and the unit prevents either my A/C, dryer, and/or hot water heater from running if need be to stay under that limit depending on the priority set for each appliance. Currently I have it set at 2.0kW but during the summer it needs to be above 5.5 for the A/C to run enough to keep the house cool. The unit does not restrict anything during off peak hours.

Re:$400 a month?

[jellomizer]

My January bill was $170.00 for Upstate NY That was for electric and Gas, in a building over 100 years old. That is Not in any way energy-star complaint.

Re:$400 a month?

[Andy Dodd]

"but directTV antennas and satellite dishes are just fine"

After a couple of legal battles, there are some federal laws that say that banning antennas and dishes in a housing development is not permitted. Many developments try to do it anyway but you can fight it if you know the right laws.

Re:$400 a month?

[drunkennewfiemidget]

I live in Canada. The weather today is -25c or so. My power bill never exceeds $46/CAD a month when I have a window AC unit going in the summer, and my gas bill never exceeds $70/mo.

The # of kWh/mo he's using would suggest to me he'd be a lot better served putting the time and energy into replacing bulbs with CFLs, turning off computers that don't need to be on, and buying higher efficiency appliances rather than those solar panels. .. or both, of course.

Re:$400 a month?

[Joe Snipe]

Dishes are allowed because someone paid the FCC to enforce the right to install one. If you can come up with a solar panel that generates ad based revenues and is steeped with kickbacks and non-compete contracts, someone will pay the FCC to enforce the right to install those on your moms roof too.

Re:$400 a month?

[MBGMorden]

It's not just being paid off - external television antennas were part of those laws too.

The whole thing is disgusting to me though. We're not living in any semblance of a free country when your neighbors can tell you what things you can and can't have on your property simply because they don't look pretty.

Re:$400 a month?

[mcvos]

The house is less than 2 years old so it should be decently insulated though the windows are only single paned.

So it's not.

Exactly. I'm amazed to read that some new houses in the US are so badly insulated that they have single paned windows. In Netherland people stopped doing that in the '60s or '70s.

Mind you, my previous house was from 1913, and before it got renovated, it had single paned stained glass windows, with wind blowing through gaps around them. Impossible to heat, so in winter I wore an extra sweater and lived next to the heater.

After it got proper insulation (including ugly windows, unfortunately), I hardly even needed the heater in winter. Good insulation matters a lot.

Re:$400 a month?

[MrSteve007]

A couple points.

1. At that latitude, the angle you mount your panels for operation would be steep enough for most snow to slide off. Also the dark color of the panels means that the snow will melt off there first. Although the snow may eventually build up at the base and block the rest from sliding off.

2. Amount of Sun. It's all about the solar insolation measurement. The feds have been logging this data for 30+ years and averaged the amount of annual sunlight in several areas in each state.

http://www.solar4power.com/solar-power-insolation-window.html

The above link is a good chart for this. The average for cities in New York is about 3.5, which equates to right around 3.5 kWh daily output for each installed 1,000 watts of generation capacity. That isn't the best, but it still is plenty. Germany has the largest number of installed PV arrays, and they are just as, is not more cloudy than New York.

I operate a 10 kw solar PV array in perpetually cloudly Seattle. We're going to see a payback of right around 10 years. Solar works just fine for us, although we do expect greatly reduced output in the winter months. The longer days during the summer, due to the high latitude, helps make up for some of that though.

http://www.jbdg.com/solar.html My array.

ROI?

[RyanSpade]

Why didn't this follow up article include a Return on Investment number? It would be nice if he would have included the cost of the install and compare it to the difference in his electric bills. I'm curious to see how long it will take the install to pay for itself.

fixed angle panels are sub-optimum

[RichMan]

Who ever installed the panels mounted them directly flat on the roof. That is bad.

They need to be angled for the best sun during the time the power need is greatest. Ideally they would be adjustable semi-annually/quarterly/monthly for the best angle. And if fixed would be biased toward the point of worst number of sun days and power need.

Doing a suboptimal installation and not accounting for sun angle is not a good installation and should be perform at a fraction of potential output.

ROI is about 12.5 years

[clonan]

I went back to his original article (the instalation). He said the estimate is that his anual utility bill will drop from 4400 a year to 1100 a year.

So I made a few assumptions.

#1-his power use will not increase. Not really likely but a future increase shouldn't change the ROI on his current investment.

#2-Utilities will just keep pace with inflation (assumed 2%)...power costs will stay porportinally expensive in the future. This is probably not ture as power prices tend to increase slightly faster than inflation. So this assumption will tend to increase the ROI.

#3-I assume he is financing it through his mortgage at about 5%

Therefore when I calculate out to 25 years I find that he would spend about $141,000 in power over the 25 years without slar. With Solar he would spend $35,233.

The Payoff date comes at about 12.5 years.