Some combo of coal, nuclear, and natural gas is probably the right measure. As noted, probably about 40% of baseline generation is coal, with nuclear too. But peak production – the extra plants that are started up when there’s really big demand – is mostly natural gas.
And, in the U.S. right now, peak demand for electricity is during hot sunny days. Which is of course when solar panels deliver the most. So currently, a new solar panel replaces some baseline generation (whatever the mix is for the area), and a bunch of natural gas. So the greenhouse benefits are better than the baseline mix that Alley Dweller reported
A lot of coal-fired power plants are being converted to natural gas now. According to the WSJ, natural gas accounted for more electricity generation than coal for the first time ever in April.
How will she use them? I believe that you can buy the circuitry to produce 110VAC 60 Hz, and arrange with your power company to feed your house while still being connected to the power grid.
You can use the cells and batteries to run some 12v DC equipment in your house, lighting for example.
I took a solar course in college. The plan was to heat water and warm the house. We calculated the heat loss from a house. The loan to buy the equipment was compared to the money saved.
I got Fargo, ND.
I heated the house, and the guy lost money. A doubled the size of the collectors, and he seriously loss money.
I cut it to half of what was needed to heat the house, and he made money hand over fist.
So I believe that she needs some figures on how she will use the electricity generated by the cells.
Thanks for the maps, Projammer.
She should wait until she replaces her roof, if it’s going to be in the next five years or so. There’s not quite enough profit in panels to make up for having to remove and re-install them in a couple years.
Panels are regularly getting slightly better and cheaper, but I don’t think anyone is expecting a big breakthrough imminently; no particular reason to wait for better/cheaper ones at this point.
Environmentally, they do make sense. Again they’ll be mostly replacing natural gas. There is an environmental cost to making them, but there’s an environmental cost to mining and transporting the natural gas, too. I don’t know of anyone who has any evidence that solar panels are a net loss environmentally.
She’s done some research on Suniva, the manufacturer of the panels, and apparently they aren’t very good stewards of the earth. She’s checking to see if she can use a different manufacturer.
There’s not really a good watchdog, I think, but the solar scorecard linked to above at least has self-reported environmental impacts. SolarWorld in particular is made in Germany and the USA, where environmental regulations are stronger than in China. But that only applies to the final assembly, not mining of the raw materials etc. As with electronics and apparel, there just isn’t a good international monitor of cradle to grave supply chain impacts. Too many countries with too little money and too many people.
(This is opinion only) In the end – I don’t know if anyone has actually studied this – maybe it makes more sense to get more of the cheapest, dirtiest panels rather than fewer greener ones, only because the per kWh pollution of any type of solar is much cleaner than coal or natgas. The differences in initial impact probably aren’t great, especially at this early stage where everything is initially sourced in countries with weak or nonexistent environmental controls anyway. I suspect the greener panels are just better at marketing themselves as such.
Huh. Well in Canada as a whole, coal only accounts for 13% of electricity with certain provinces (like Alberta unsurprisingly) using it a bunch more. I would assume that there is probably a similar diversity in the States.
The grid mix in Canada is not the same as the US, as pointed out above. As of 2014, in the USA, more electricity comes from coal than any other source. Even if natural gas exceeded coal for one month, that’s just that month vs the entire 2014 average. And natural gas, while twice as clean as coal, is still much dirtier than solar and wrought with its own problems (like fracking). Here’s a relevant natgeo article. And utility-scale hydro absolutely devastates local ecosystems, improving pollution at the cost of biodiversity, which depending on who you ask may or may not be an environmental boon at all.
Coal, gas, and large hydro are not realistic solutions to a cleaner grid – whatever incremental scrubbing technologies are applied to them, in the end they are still releasing stored underground carbon into the atmosphere or drastically altering habitats to create dams.
In the context of national decisions, there are difficult economics to be weighed. But in the context of this discussion about the environmental impacts alone, they are simply dirty, dirty, dirty. Much more so than solar or any other true renewable.
To really meaningfully change things, we need widespread adoption of baseload nuclear with really good waste storage policies (that don’t exist yet) combined with geo + wind + pv + microhydro in the geographically appropriate areas – and even that probably won’t be enough, because most of the weight will still be carried by nuclear, and we haven’t yet solved the supply chain issues of national-scale renewable rollouts (not to mention building a smart grid that can support them).
In the environmental context, coal vs natural gas is a completely moot point and serves (deliberately) as a delaying tactic to forestall actually cleaner energy.
I’d second the recommendation to wait until she replaces her roof, if it’s work that will be soon. No sense in putting the panels up on an older roof. The work will just have to be re-done.
Here in sunny CA, I can say that having solar has been amazing. My bills have sliced to 20% of what they used to, and that’s during the Summer. We’ll see how it goes during the Winter months, with lower electric usage.
Very low natural gas in the Summer. I think I’m paying about $12/month, but I backed that out of my number above. The hot water heater is on natural gas. Also the stove.
The heater is also natural gas, but we don’t run it much given the location and the fact that we tend to like the house cold.
Basically, this Spring I was returning electricity to the grid. I expect Fall will be the same. I run the AC on hot days, but my electrical bill is trivial. Of course, the utility company here has a “true up” once a year, so no cash back until this Fall.
Are there any panel manufacturers who power their factory entirely using their own panels? Or at least, which have panels producing the same average power as consumed by their plant (to allow for non-constant sunshine)?
Yeah, but as I pointed out even further above, Massachusetts where the OP’s sister lives does not and is in line with Canada’s coal electricity generation. We’re not talking about a national strategy in this thread. It’s whether an individual household is making a environmental difference when installing solar panels.
It’s almost 70% fossil fuels there. Nearly 60% natural gas and 10% coal (http://www.eia.gov/state/?sid=MA#tabs-4) . This is not something to be proud of and certainly not better than household solar (although household solar alone won’t do much good anyway, since household energy use is only 30% of state total, and electricity is only a portion of that vs home oil heating).
Natural gas is not a clean alternative to solar. It is slightly less dirty than coal but still terrible. It’s not about coal vs solar but fossil fuels vs renewables (with solar being the only practical choice for most households due to geography ).
But Massachusetts seems to have green energy choices from some utilities that the op the might want to look into vs solar at home .
