Coal in a hard place.. expecte to produce < 30% of electricity by end of decade

Mileage will vary. National stats without bias are usually a better way to go than personal anecdotes. The low tech and high solar efficiency of the solar hot water heaters usually makes it part of the mix.

 

I priced solar DHW a few months ago for central NM.
$6000 installed before tax credits to collect about 250 kwh a month of heated water. This works out to $2/watt installed cost before subsidy.

For comparison, switching from electric hot water to gas will cost me $1300 for parts+ installation (gas pipe present), and about 100 cents/therm. A therm is 30 kwh. In terms of relative cost, the solar solution costed as a 4% apr loan over 30 years would cost $22.44 for the capitalization of the $4700 difference. I would save about $8 a month in current very low NG costs, so the monthly 250 kwh of pollution free energy is 5.76 cents a kwh extra.

I looked into electric heaters with air heat exchangers but could not convince myself that the annual COP for my locale would make the option a good one, and I am influenced by my electricity being 100% coal sourced.

In the end I've decided to install gas DHW, but that was as much to avoid the hassles of trying to deal with my moronic republican neighborhood Assn as it was money.

 

Since you were already electric hot water, would $6K in solar electric have worked?

 

Ignoring the issues I faced with my neighborhood Assn, I think you are asking if $6k of PV would provide the same amount of hot water heating. A PV array of 1.5-1.75 kw is needed in my locale for equivalent water heating. It would have to be part of a larger array to bring down total costs to $6-$7/watt, but the water heating fraction would cost before subsidy somewhere in the range of $9- 12.25K.

AG does not have much of a clue, although it is true that local solar DHW is very much a ymmv. Small systems are expensive $/watt wise, while big systems may not use all the heat generated. In the end, I'm happy with my outcome of using NG to heat water, and putting the saved money into other energy savings projects instead. One aspect of costs I have not seen considered in this thread is fraction of cost that stays local or domestic. Solar DHW is a winner hands down there.

By the way, solar DHW can sometimes be a DIY project. Then it is a no brainer. Solar heating can also have excellent money savings if it is combined with home heating, but only if installed competently, and at the time the home is being built.

 

That has not been the problem in the past. Getting the US to do anything has been very hard. But since it uses about 25% of all fossil fuels, it could in theory reduce the worldwide production of ghg by 25%. Nothing to sneeze at.

Check out the solar panel usage by country (wikipedia):
Total photovoltaic peak power capacity (MWp)[55][56]
Country or RegionTotal
2010Total
2011[57]
World 39,778 67,350
European Union 29,328 50,300
Germany 17,320 24,700
Spain 3,892 4,200
Japan 3,617 4,700
Italy 3,502 12,500
United States 2,519 4,200
Czech Republic 1,953 1,960
France 1,025 2,500
China 893 2,900
Belgium 803 1,500
South Korea 573
Australia 504 1,200
Greece 206 550
Canada 200 500
India 189 450
Slovakia 145 500
Portugal 131
Austria 103 200
Switzerland 100
Netherlands 97
United Kingdom 72 750
Israel 61 190
Slovenia 36
Mexico 28
Luxembourg 27
Bulgaria 18 100
Malaysia 15
Sweden 10
Finland 9.6
Norway 9.2
Denmark 7.1
Cyprus 6.2
Turkey 6.0
Ukraine 0 140

 

Solar hot water systems that raise water to the 120F-140F needed for domestic hot water are more complex and much more expensive that systems that just raise the water to 90F-100F. That's where simple DIY systems have a place.

If your incoming water from the ground or mains is at 60F and you raise it to 90F with a simple DIY system, you have just provided 1/2 the energy required to raise it to 120F for a 50% savings on your fuel consumption. I'm still not going to do that though because my hot water use isn't big enough to make it worthwhile for me.

 

Interesting. So for equivalent energy savings on hot water, a solar hot water heater was $6K and solar electric would have been $9k. Probably more if just enough to do hot water if I read you right that getting a small solar electric would be higher cost per KW than a larger system.

 

Yes, you read correctly.
Here is a balanced review of solar DHW vs PV+heat exchanger. Is this Corwyn's company ?
I'm pretty confident in saying that a competently installed solar DHW system will last 30 years, while no one can say the same for heat exchangers.

Generalizations supporting either approach is a bad idea. You have to know the locale, heated water consumption details, and local installation costs to make an informed decision.

 

I couldn't resist organizing the table Corwyn copied.

Any idea why there's lots of space below?

	Column 1	Column 2	Column 3
0	[tr][th]Country or Region[/th][th]Total 2010[/th][th]Total 2011[57][/th][/tr]
1	[tr][td]World[/td][td]39	778[/td][td]67	350[/td][/tr]
2	[tr][td] European Union[/td][td]29	328[/td][td]50	300[/td][/tr]
3	[tr][td]Germany[/td][td]17	320[/td][td]24	700[/td][/tr]
4	[tr][td]Spain[/td][td]3	892[/td][td]4	200[/td][/tr]
5	[tr][td]Japan[/td][td]3	617[/td][td]4	700[/td][/tr]
6	[tr][td]Italy[/td][td]3	502[/td][td]12	500[/td][/tr]
7	[tr][td]United States[/td][td]2	519[/td][td]4	200[/td][/tr]
8	[tr][td]Czech Republic[/td][td]1	953[/td][td]1	960[/td][/tr]
9	[tr][td]France[/td][td]1	025[/td][td]2	500[/td][/tr]
10	[tr][td]China[/td][td]893[/td][td]2	900[/td][/tr]
11	[tr][td]Belgium[/td][td]803[/td][td]1	500[/td][/tr]
12	[tr][td]South Korea[/td][td]573[/td][/tr]
13	[tr][td]Australia[/td][td]504[/td][td]1	200[/td][/tr]
14	[tr][td]Greece[/td][td]206[/td][td]550[/td][/tr]
15	[tr][td]Canada[/td][td]200[/td][td]500[/td][/tr]
16	[tr][td]India[/td][td]189[/td][td]450[/td][/tr]
17	[tr][td]Slovakia[/td][td]145[/td][td]500[/td][/tr]
18	[tr][td]Portugal[/td][td]131[/td][/tr]
19	[tr][td]Austria[/td][td]103[/td][td]200[/td][/tr]
20	[tr][td]Switzerland[/td][td]100[/td][/tr]
21	[tr][td]Netherlands[/td][td]97[/td][/tr]
22	[tr][td]United Kingdom[/td][td]72[/td][td]750[/td][/tr]
23	[tr][td]Israel[/td][td]61[/td][td]190[/td][/tr]
24	[tr][td]Slovenia[/td][td]36[/td][/tr]
25	[tr][td]Mexico[/td][td]28[/td][/tr]
26	[tr][td]Luxembourg[/td][td]27[/td][/tr]
27	[tr][td]Bulgaria[/td][td]18[/td][td]100[/td][/tr]
28	[tr][td]Malaysia[/td][td]15[/td][td][/td][/tr]
29	[tr][td]Sweden[/td][td]10[/td][td][/td][/tr]
30	[tr][td]Finland[/td][td]9.6[/td][td][/td][/tr]
31	[tr][td]Norway[/td][td]9.2[/td][td][/td][/tr]
32	[tr][td]Denmark[/td][td]7.1[/td][td][/td][/tr]
33	[tr][td]Cyprus[/td][td]6.2[/td][td][/td][/tr]
34	[tr][td]Turkey[/td][td]6.0[/td][td][/td][/tr]
35	[tr][td]Ukraine[/td][td]0[/td][td]140[/td][/tr]

 

The US has done much, and most of it has been to encourage more energy use, not discourage it I am pessimistic that a large portion of our energy ever comes from solar, it simply is much more expensive, but... it is cost efficient enough to be much greater than it is today. I would not rule out 25% as costs continue to go down. To get there we must not waste money on pork barrel projects. Feed through tarrifs along with tax credits appear to be the best course. Germany is still only about 4% after all their spending. Wind is cost effective today. It can be drastically expanded with good grid management. Many states are building large amounts of wind. Finally converting from inefficient coal plants to 40%-60% efficient natural gas plants to both handle peaks and shut down on valleys of demand can cut ghg from those plants to less than 1/3 of the ghg they are producing now, and cut down SO2, NOx, particulates, and mercury much more.

Finally efficient homes and cars are important. Plug in cars seems to be todays solution, efficiency can only go so far with all gasoline cars.

For all these things there are political road blocks.

 

No it is not, but I am familiar with the principals of both companies involved.

Yes, exactly. What you should do for heating is dependent on many factors, and no one solution fits everyone. I will say that for the majority of people (that I have personal knowledge of), weatherization is the number one priority. Switching fuels can be favorable, but a lot depends on ones local infrastructure. There are places in Maine where you can get wood pellets delivered in a (modified) oil tanker truck, for example, but it is not available everywhere. Converting the 80% of Mainers who use oil to natural gas would be a huge project.

 

For me, PV is cheaper per kWh than Electric Company rates. Today. No paybacks involved. At the current rate, that should be true for the average American in a year or so.

Germany exceeded 50% back in May. http://www.treehugger.com/energy-policy/half-germany-was-powered-solar.html

 

It also has links about heat pump water heaters and natural gas water heaters. For the bulk of the people these are better choices. Show me where they say solar hot water heaters are good for a good portion of the population? They simply are not.

Yes but the doe does not compare the cost to the benefits on that site. If they did, cost/benefit is higher for efficient water heater plus PV. For most of the country with cheap abundant natural gas, there is no reason not to use a natural gas water heater. If you want to reduce carbon footprint use PV or wind for your electricity. That is what I do.

This is one of those confusing things, that gets people to make really stupid mistakes when it comes to energy policy. Heating the water with the sun is more efficient than producing electricity, but.... who really cares if it uses more of the sun. The important things are cost, energy savings, and what it does to your roof. Here Solar water heaters are clear losers for most people in the US without swimming pools. They might be better for 1 out of 10,000 other people, but you need to screen those, and I bet the the numbers are smaller. We have tankless natural gas, and heat pump electric water heaters, and when compared to them solar improves energy use very little.

lol. Because solar water heaters can't payback in anyone's lifetime here, we have huge subsidies. Federal is 30% up to $2000, then municipal and state kicks in about another 35%. To get the money you need to use an approved installer, which means you need to pay a fair wage, making inexpensive systems not work. When you hack out the numbers versus Solar PV they make no sense. Also other peoples electric bills go up to pay for your subsidy if its solar hot water, which does nothing to help peak demand. At least the solar PV provides electricity for peak air conditioning demand which doesn't raise prices as much for everyone else. This is why at today's prices solar water heaters are such a boon doggle, the subsidies only help the installers, and we can help them more by getting more usefull solar PV. In southern california IIRC the payback on solar water heaters is 1.5 times as long as solar PV. If you are going to deal with people on your roof, why not do the right thing. In washington state with all the hydro, you are using a great deal of clean energy anyway.

Solar water heaters are like beta max. People still argue that its better, but we are in the land of blue ray, dvr, and streaming content. Who cares if beta was better in the dark ages, it sucks now. Same for solar water heaters.

 

All I want is to make natural gas available to them. If oil gets to be $10/gallon, which it may be in the near future, I doubt there will be many complaints to switch to things other than heating oil. We should not be short sighted and assume oil prices will not get worse. If wood chips or other fuels make sense for maine, by all means I am not against that. What I am against is subsidizing heating oil each year, while not helping people move away from it.

Certainly, whatever your power source, efficiency matters, and that includes insulating the dwelling.

 

That's nice but you were you were saying solar hot water did not pay and was not efficient and DOE says the opposite and you claimed DOE did not say it.

As you saw with SB's numbers, the solar hot water was more economical than solar electric for the hot water. That equation seems to be constant and many of the solar installers quote both systems when quoting a complete home solar power system. The efficiency of solar hot water system is hard to beat.

 

That's why I said for many it is good today. I buy inexpensive wind, for less than you can buy electricity from your grid. I may move, and payback is around 10 years even with the large subsidies here for solar, because of installation. It is going into all the new homes though, as they are built with it on the roof. The average american doesn't own a home But for homeowners in many states the numbers make sense now. I had a friend just install solar, when he had to repair his roof, and he could not believe how much the utility was kicking in. He need to have that roof labor anyway.

You got to be carefull of these funky instantaneous numbers. We have places that have been at 100% wind too Germany is at about 4% of total consumption from solar. This works out as better than a 4% contribution though, since they can buy cheap french nuclear energy at night.

 

Don't paraphrase, you really have been idiotic about this. Really solar heat is like beta max, its out dated. I said the DOE did not make any claims about these hot water heaters, they have all the tech on their page. I also said that compared to solar PV solar water heaters make no sense, and you can save more energy with pv. If you have pv with a heat pump water heater you get 100% of your hot water by solar means. It also has quicker payback. Most of the time though natural gas water heaters are so efficient it makes no sense to replace them. I take it you love some old tech, and have no clue why it is bad. Some people collect vinal, some have beta max, but for the grand majority we use something else.

I am ignoring that user. Put the numbers out if they are actually good. The mistake most people make is not using the installed cost of the the systems, and not understanding that solar hot water heaters still need energy to heat water. If those figures were included I'll be happy to look at them. If not when he shows his work, I'm sure it will show that its not a faster payback, unless something is up.

 

As I said, piping natural gas to the majority of Mainers would be a huge undertaking, our population densities are one issue. We still have many places without electric lines. I suspect that the best way to do it would be to burn it in an electric plant, and convert people to electric heat pumps.

I have been trying to push some simple energy saving devices instead of, or in addition to oil subsides for the poor, and meeting much resistance. 'Pulling' seems to be a better method.

 

Is that paraphrasing? Sorry DOE website disagreed with your opinions regarding solar hot water systems.

 

Geothermal heat pumps are the most effective things here, unfortunately they are expensive to add to old houses. Definitely electric is a possible solution. I just see as it is 40 years of keeping a large portion of the population on oil. We should at least draft a 10 year plan to get people off the stuff. Perhaps some people to natural gas, some to wood chips, and others to efficient electric in a reasonable time frame.

Subsidies for the poor normally are fairly clean energy, and paid for by other users. Unfortunately this good system is from local regulations, and other areas are not as fortunate. The municipal utility has people whose only job is to help customers become more efficient, and there is a small charge every month to help pay for those that can not pay their bills. What energy saving devices have you been trying to employ. I have friends getting masters in architecture at UT, and they all have had coursework in green building. I'd like to hear what modifications you are thinking about, and run it by them and their proffesors.