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Solar at Home

Solar at Home


The trials, tribulations and rewards of going solar
Solar at Home Home

Someone please tell the Obamas: Solar works now!

The views expressed are those of the author and are not necessarily those of Scientific American.


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Editor’s Note: Scientific American‘s George Musser has been chronicling his experiences installing solar panels in Solar at Home (formerly 60-Second Solar). Read his introduction here and see all posts here.

Hren's 1932 bungalow with various forms of solar energyOne of the hardest thing about installing solar panels is getting good information, so I’m happy to report that a new book by fellow solar bloggers Stephen and Rebekah Hren, A Solar Buyer’s Guide, is coming out in a couple of weeks. I invited them to write a guest blog on where they think home solar technology stands.

Many people feel inclined to wait on the sidelines until some breakthrough makes solar energy "work" or until it becomes "affordable." Some of those people are apparently the Obamas, who have refused to allow free installation of solar panels on their roof! But even though solar installations are generally not free, they are still a good deal.

We are quite capable of designing buildings and lives in a sustainable way powered by the sun, and much of the basic technology goes back millennia. Yet historically it has taken a crisis of energy supply or ecological devastation to encourage widespread use of solar energy. After they had burned all there accessible forests, ancient Romans developed the heliocaminus, or "sun furnace," a south-facing room that heated their homes in winter. Similarly, once the British had eliminated their woodlands during the late Middle Ages, they also discovered the joys of solar heating. Access to the sun became a fundamental right in Britain for any building, eventually codified in the Law of Ancient Lights. Today, the impetus comes from global climate disruption and the peaking of per-capita fossil energy supplies.

Why solar has been regarded as a technology of last resort is a mystery to us, because it can be extremely cost-effective. We can harvest the sun’s energy in multiple ways. Instead of just using solar energy to heat our homes in winter, we can heat our water, cook our food, and of course convert solar energy into electricity. You can make your home carbon-free, as we have done with our 1932 bungalow (see photo above), or you can put up a solar water heater or smaller photovoltaic (PV) system that offsets only some of your home’s or office’s fossil energy use.

Cost-effectiveness depends not only on a wide array of varying federal, state, and local incentives, but also on the efficiency of the system. Turning solar energy into heat is simpler and typically more efficient than converting it to electricity, so paybacks on solar water heaters are often quicker than for PV systems, but check out your local situation before making any assumptions. Some areas have spectacular incentives for PV at the moment. While a system of patchwork incentives is obviously less than ideal, until the mammoth subsidies and tax breaks for the fossil fuel industries are removed and a carbon cap or tax is established to account for their detrimental effects, such breaks for solar energy allow it to be on a more level playing field. They help create economies of scale and drive technological progress that should help reduce prices in the future.

Technology is advancing all the time. One very cool gadget that is now being incorporated into solar electric panels is the microinverter, a topic of past Solar at Home blog posts (here and here). These sophisticated gizmos are capable of converting the DC juice being pumped out by each individual PV module directly into AC power right there at the module.

One huge advantage of the microinverter is that it mitigates shading problems on the PV array. When installed on the roof, an array will often suffer from partial shading some time during the day due to trees, another building, chimneys, and so on. Conventionally, the output from an array of PV modules is sent to one main inverter, and even small amounts of shade can have disproportionately large effects on the electricity output due to the way the modules and arrays are wired. Without microinverters, the shading of just one PV module could possibly disrupt production for the whole array. But with microinverters, the production from the shaded modules can be isolated, allowing the solar juice to keep flowing from the rest of the array.

Using microinverters, PV array wiring is faster and more straightforward, and the power is easier to shut off in an emergency. Microinverters also allow web-based production monitoring of individual PV modules, providing entertainment when the office gets slow. Maybe no one explained these nifty things to the White House.

As the novelist William Gibson quipped, the future is here now; it’s just not widely distributed yet. The technology to harvest solar energy effectively is already available, but it’s up to us to make its implementation a priority, despite what our First Family does. From high-tech gadgetry like the new microinverters to the more prosaic technologies that can heat our buildings and hot water, solar energy is varied in what it can accomplish. There’s no need to wait for some theoretical time in the future, because solar power is here and ready now.

The Hren’s home, courtesy of them





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  1. 1. jtdwyer 7:24 am 09/23/2010

    If cost-effectiveness for the homeowner/investor depends on federal, state, and local incentives, cost-effectiveness for the taxpayers at all levels of government depend on the benefit provided to all of us who do not live in the investor’s home and pay their bills.

    The only benefit of purchaser incentives that I can see for taxpayers is possible deferment of new utility power generation facility investments, in which case it is more directly the utility ratepayers rather than taxpayers that benefit. Why don’t the power utilities subsidize homeowner purchase of PV equipment rather than the taxpayer?

    I suspect that the actual installation of PV equipment on my neighbors’ houses provides little if any benefit to me. As a result, I see no reason why my taxes should be paid to my neighbors to lower their utility bills! Have I missed something here, besides altruism?

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  2. 2. willlinn 9:24 am 09/23/2010

    This is absolutely right

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  3. 3. thecarbonfreehome 10:14 am 09/23/2010

    Agreed that the current situation is less than perfect. Renewable energy like solar currently needs incentives to compete with traditional fossil fuels because of three factors: 1) Subsidies of the fossil fuel industry at over $10 billion/year (see:http://priceofoil.org/fossil-fuel-subsidies); 2) Externalities associated with fossil fuel extraction and consumption are not priced into the cost (everything from climate disruption to polluted water supplies, and some would say war in the Middle East); and 3) the finite nature of fossil fuels means that as a nation we
    become dependent on others for their supply, and even that foreign supply will eventually run out, meaning civilization will no longer be possible.

    It is unfortunate that government finds it easier to lower the price of renewable energy through tax breaks and other incentives rather than pricing fossil fuels at their real cost. Doing the latter would produce tax revenue to offset the damage done by fossil fuels, make renewable energy competitive without additional subsidies, and force us to use our limited energy supplies more efficiently and judiciously because of their overall higher cost. Perhaps if it were possible to find politicians with more backbone and foresight, we could do things the right way, but we won’t be holding our breath.

    Stephen and Rebekah Hren
    http://www.thecarbonfreehome.com

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  4. 4. Fossilnut 10:57 am 09/23/2010

    My brother in Kentucky has gone through three sets of solar power systems since the 1980′s. It’s cost him tens of thousands over the cost of conventional heating.

    He loves it. It’s a hobby for him and he’s recovered most of the cost by installing solar heating for others….at thousands of dollars

    Solar heating is a money pit in installation, maintenance and replacement costs….and you still need a conventional source in your home (and all the infrastructure costs).

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  5. 5. TTLG 11:19 am 09/23/2010

    Good for the Obamas. Barack Obama seems to be one of the few politicians who realize they were elected to serve the public, not the people or industries who gave them the most campaign donations. I am a serious environmentalist and techno geek. I built my first solar cell project back when I was 12 years old. But the simple fact is that solar does not make economic sense for most people in most situations, even with the steal-from-Peter-to-pay-Paul incentives that exist now. Nor does it make environmental sense to be installing systems which will likely to be obsolete before they pay back the resources used to make them. What most people need to do is to work on conservation measures. What we need to do as a country is to do the research needed to get the efficiencies, reliability and cost effectiveness to where it does make sense to use these.

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  6. 6. thecarbonfreehome 11:19 am 09/23/2010

    Making active solar heating systems work well can be tricky, especially when installed on roofs (and especially when they are home-made). Maintenance is much lower if the system is installed on a south-facing wall, because they aren’t exposed to rain and summer sun. They also perform better because they help circulate the air in the room that’s being heated by drawing air up near the ceiling downward, as opposed to a roof-mount where most of the hot air gets stuck up at the ceiling. Using solar for heating water is a safer bet because hot water is used year-round, and should usually be the first solar thermal application for any home or office. For places with large heating loads (HDD > 4000 or so), a combined solar hot water/radiant heating system is probably worthwhile.

    Properly designed passive solar heating can cost very little and greatly reduce conventional heating sources, meaning not just lower utility bills but smaller units and less frequent breakdowns. This can be done by adding a solar porch or greenhouse to most residences. Details of all these choices are thoroughly explained in our new book. ;)

    Stephen and Rebekah Hren http://www.thecarbonfreehome.com

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  7. 7. thecarbonfreehome 11:31 am 09/23/2010

    Agreed on the need for conservation. However, both solar thermal and solar electric technologies have been around for over a century now, and the energy payback is generally estimated to be within 2-7 years (depending on type of installation and location). Most installations are guaranteed for 20 years or more. If you still have your doubts about PV, that’s understandable, as different analyses reach widely divergent conclusions. But solar water heating is a no brainer.

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  8. 8. jtdwyer 11:48 am 09/23/2010

    Thanks for the straight discussion. You got me on the water heater…

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  9. 9. jerryd 3:22 pm 09/23/2010

    PV is now under $2k/kw for panels and if one does their own contracting, can be installed for under $3k/kw, sunelec.com among other suppliers. This is cheaper than any utility power except in hydro areas.

    A solar CSP unit is only a 5hp steam/heat engine, a 3kw alternator, a 200sq’ trough collector that could supply both heat and electric for a home and EV’s. In mass production no reason it could not be made for under $5k. With an optional burner can be co fired by biomass, etc if more power, heat needed and the sun is not shining.

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  10. 10. jerryd 3:28 pm 09/23/2010

    Here’s what someone should tell congress, Obama and do. It’s the real subsidies going to oil, coal that keep RE from being done.

    Real stimulus, balancing the budget at little cost.

    Balancing the budget, energy independence, fighting terror, corporate welfare at little cost is something we not only can but have to do. Especially because they have the same cause, corporate welfare for big oil, coal.

    We every year subsidize big oil by our Persian Gulf military programs, fighting oil wars which is the cause of most terrorism, by $600B/yr. The only reason we are there is to support/subsidize big oil. Once we are close to energy independence there is no need for us being there or fight such wars, saving our soldiers lives and from devastating injuries, not to mention $600B/year. Ask most any military person and they will tell you it’s all about oil, not freedom or anything else.

    Next we spend $400B for overseas oil and that’s going up, that directly support Iran, oil dictators and the people/war we are fighting, terrorists. So every $ we spend on oil, 40% goes to those who are fighting us. Is that smart, paying both sides of the wars? Let’s get out of that mess and let them kill each other, not us.

    Now add tax breaks, sweetheart royalty deals, etc and this comes to $1.1T/yr you pay now mostly in taxes!!

    Coal’s large subsidies comes from the massive pollution from mining to burning that destroys our land, water, air, buildings, bridges, health costing another $300B/yr in higher taxes, health care costs, mostly you pay like oil, in your taxes, health insurance , etc costs.

    Interestingly this comes to about our budget deficit!! But how do we fix it? It’s surprisingly simple needing little cost or regulation. In fact can cost far less, lower regulations in just 5 yrs than now. The solution is having those who cause the problem, pay it’s real cost and letting a true free market work.

    The method is a tax and rebate setup where oil, coal are taxed their true cost and the revenue from that is rebated back to the public in a rebate of 75% or the revenue. This covers the higher costs though many smart people will use that, about $300/month, to buy a high mileage car and make one’s home more eff by insulating, more eff and alternative energy equipment to lower those costs.

    Putting on new insulation shells, windows, alt energy, etc on homes/buildings will put the construction workers back to work, start many new businesses, increase eff car, alternative vehicle sales that will stimulate the economy by 3 million new jobs with another 3 million jobs to support them conservatively. Fla especially will benefit.

    The beauty of this is it’s paid for by energy savings and by oil dictators, terrorists in large part because it will drive down the price of oil so they pay 50% of it and hopefully, destroy them or at least make them weak!! The rest comes from higher tax receipts from increased jobs and less unemployment, pollution and health care costs.

    All the gov needs to do it tax the fossil fuels so a real free market can work. And through the SBA do start up and small business loans of under $50k which can’t be had from banks, loans for home eff, alt energy work through utilities or other orgs as banks won’t do those either. The cost of these paid for in energy savings by repaid loans and increased tax revenue means the gov is likely to make a profit, not a loss.

    They also need to make it legal for anyone to sell electricity and make utilities pay full price they charge for it minus 10% for being the middleman, real net metering. This will allow businesses to lease AE equipment at little to no cost to consumers out of pocket, paid for in energy savings. Since lessors will lose if equipment is not good, they will only do good work, cutting many scams that might rise otherwise.

    The other 25% revenue should go directly to pay down the national debt these subsides drove up. All for being truly fiscally conservative and smart. Or we can stay at war, go broke and become a has been nation to subsidize corporate welfare. Send this to your congress people and demand they implement it. It’s the only real patriotic thing to do for national and economic security.

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  11. 11. thecarbonfreehome 3:55 pm 09/23/2010

    Agreed that fossil fuels are more heavily subsidized than the conservative $10B/yr number we mentioned earlier. Your $3/installed watt number for a diy is probably not realistic, however, since in most places you would need to be a qualified electrician to get your system connected to the grid. And with racking, inverters, wiring, etc. an installed price of less than $5/w is unlikely. We like your mention of concentrating solar power, a very underutilized resource on the utility scale. A huge 1,000 MW project was just approved for construction in the Mojave desert:

    http://www.elp.com/index/display/article-display/articles/electric-light-power/renewable-energy/solar/2010/09/Solar_Millennium__Chevron_win_OK_for_1_000_MW_solar_thermal_plant.html

    Stephen and Rebekah Hren http://www.thecarbonfreehome.com

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  12. 12. celia88 4:06 pm 09/23/2010

    Solar energy is no doubt the most abundance and powerful resources we can get. Even though it will cost some money to install it, but it gets energy from the sun, which is free and accessible most of the time. Also, it is clean! In the past few years, due to the development of industry, the emission of carbon dioxide and other waste gases have rapidly increased. Global warming has become a more and more severe problem for our mother earth. Mother earth is mad! The frequently happened global diseases, earthquakes, and drought are warning from her. If we keep doing this, what we will leave for our descendants will be nothing but a dirty earth. On the other hand, the fossil fuel industry is a expensive and burden for our country. We may need to relay on other countries for some kinds of the fossil fuel, which can be a restriction for the related industry. Solar panels are also a safe energy generator for us. It won’t explode or leak dangerous gases; there are no such big possibilities to threaten our lives. Even if it broke, it is easy to clean and replace. Overall, it is the best choice for us in this society.

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  13. 13. jonryker 12:28 am 09/24/2010

    If solar was cost effective, as the authors state, there would be no need for subsidies…..

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  14. 14. oldvic 4:27 am 09/24/2010

    ‘Perhaps if it were possible to find politicians with more backbone and foresight, we could do things the right way, but we won’t be holding our breath.’

    This is easy. If we the people vote for politicians with such qualities, problem solved.

    Uh-oh… sorry, for a moment there I forgot the realities of politics. We only vote for those who promise us what we want, not what we need.

    We certainly get what we deserve.

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  15. 15. nofinance 4:50 am 09/24/2010

    Making active solar heating systems work well can be tricky, especially when installed on roofs (and especially when they are home-made). Maintenance is much lower if the system is installed on a south-facing wall, because they aren’t exposed to rain and summer sun.

    Chris,
    <a href="http://www.financialcrisis2009.org">Financial Crisis</a>

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  16. 16. thecarbonfreehome 9:01 am 09/24/2010

    Please see comment #3.

    Link to this
  17. 17. thecarbonfreehome 9:03 am 09/24/2010

    There’s also the issue of an entrenched political system that allows pretty much zero chance for new voices to be heard and potentially elected.

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  18. 18. tangotommy 5:37 pm 09/28/2010

    Excellent arguments, but one big problem…they make sense. They’ll never fly in Washington, D.C.

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  19. 19. bucketofsquid 9:45 am 09/29/2010

    I’ve been looking at solar energy for over a decade. There are a number of issues preventing my adopting it for use.
    1. I’m not an electrcian and can’t afford to hire one to install it.
    2. Most information on solar and it’s benefits are from southern states and I live in Nebraska.
    3. I have a large tree that shades my roof on the south side.
    4. Until recently all solar cell manufacturing produced huge amounts of toxic waste. I have not found current data for the latest new methods.
    5. Batteries cost money and take up space.

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  20. 20. Greenovation.TV 3:47 pm 10/13/2010

    George – thanks for this series!!

    Next week we will be installing 8.1kw SunPower array on the roof of our 109-year-old home in the Old West Side Historic District of Ann Arbor, MI. We will be 100% electric with our geothermal heating and cooling system. This will allow us to be the oldest house in America to achieve net zero energy and the first net-zero home restoration in a historic district. You can watch a video about our project at http://www.Greenovation.TV

    CNN reported recently that there are only 100 net-zero homes in America. Almost all of them are new homes. But, building net net zero homes won’t reduce our current consumption – only investing in making old homes more efficient will lower our carbon out put.

    As for finances . . . if we had kept the home’s 1957 Mueller Climatrol furnace and done no energy upgrades, we would have spent $77,400 over 20 years. By investing in net-zero we will NET $27,000. That’s a $104,000 swing and it doesn’t include the added value to our home.

    Would love hear from like-minded folks or anyone who wants to learn how we made our house net-zero matt[at]greenovation.TV (can also find us on Facebook).

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  21. 21. doug 1 7:12 am 11/5/2010

    Great article. Good to see Solar in all its myriad forms are becoming more practical. As much as the author hopes that someone would tell Obama that solar works, I would even more wish that Obama would have his Nobel Prize winning nuclear pysicist (Those are REAL Nobel Prizes unlike the other Nobels prizes that administration folk have won in the past)and Cabinet Member/Sect’y of Energy Dr Stephen Chu, talk to the people about a major new program on the scale of FDR’s 1933 Tennessee Valley Authority whereby 100 1-gigawatt nuclear reactors would be built in 10 years under a federal charter and which would be secured by a new federal service similar to the Coast Guard, charged with safety and security, and empowered to act wherever those standards are not observed, effectively taking away the fear that a for-profit industry would put our national energy/safety and security at risk. Of couse, some anti-science types will drag up old fears but really their religion is obsolete and prevents our nation from advancing and maintianing the primacy we had for so long. We can still have it. US designs are being installed in China faster than their high speed rail system…and a good thing too. So, solar is nice, and will be even nicer once we get it into geosynchronous orbit, but reall, Mr Obama if he is to be told anything should be told that nuclear works, and will take us to secure future if we do it right, and keeping it public, transparent, and secured by dedicated public servants similar to our military members can do it.
    Also, it is one big gov’t program Obama’s political opponents would probably support since it invests in a sector of our infrastructure that makes our nation competitive and secure, while maintaining our primacy in science/technology and business.

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  22. 22. vernongetzler 11:28 am 11/9/2010

    Well, it’s amazing. The miracle has been done. Hat’s off. Well done, as we know that “hard work always pays off”, after a long struggle with sincere effort it’s done.
    ———–
    vernon
    <a href="http://www.motorhomeinsurance.org/short-term-motorhome-insurance">Insurance Comparison</a>

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  23. 23. rationalrevolution 12:25 pm 01/24/2011

    I have a book at home that was my grandpas from the early 1970s on how to get off the grid. It has about 10 examples in it off off-the-grid houses from built in the 1960s using mostly wind and solar power, plus efficient building techniques, that are 100% off-the-grid and had all the modern conveniences of the time (I think most used evaporative cooling for "AC" or were in non-AC needing climates). They have pictures and everything, they were nice and large houses, I think the biggest was like a 4,000 sq/ft home.

    Basically, if it could be done back then, it can certainly be done now….

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  24. 24. doug l 1:39 am 01/26/2011

    Nuclear power, in particular the next generation of small modular reactors and advanced thorium reactors work even better. I wonder why Steven Chu isn’t telling the Obamas that. As for Solar…what’s not to like…and as soon as solar can power a factory that makes solar power panels, it will be a good time to use it in the limited scenarios where it makes good sense…but it’s not quite ready for prime time. Cheers.

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  25. 25. greenwise1 12:09 pm 02/1/2011

    I also recommend working with a good installer who can prepare the paperwork for the rebates that you qualify for. Many localities still have rebates available, boosting return on investment. My ROI for solar panels is about 10%. All the details are spelled out here: http://livinggreenandsavingenergy.com/my-experience-with-solar-panels.html

    Link to this
  26. 26. greenwise1 12:10 pm 02/1/2011

    I also recommend working with a good installer who can prepare the paperwork for the rebates that you qualify for. Many localities still have rebates available, boosting return on investment. My ROI for solar panels is about 10%. All the details are spelled out here: http://livinggreenandsavingenergy.com/my-experience-with-solar-panels.html

    Link to this
  27. 27. Newfiegeo 9:50 am 02/3/2011

    What about the subsidies that YOU recieve wrt to your consuption of fossil fuels. I don’t use any such form for my energy needs so why should my taxes be used to pay for your energy benefit.
    My thought is that people who use fossil fuels should pay for the entire cost of those energy sources and that current subsidies to the fossil fuel industries should be diverted to allternative energy for at least as long as the fossil fuel industry has recieved this benefit.
    A more forward thinking approach would include heavy taxes levied against fossil fuels. These taxes could then be used to push alternative energy forward faster just as we did with fossil fuels in the past.

    M

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  28. 28. SolarVV 7:01 am 05/29/2011

    Dear Sirs,
    Are you familiar with the concept of energy-active-buildings?
    The roof and south facades are made of gelioprofilya (energy-active roof and facade). They convert solar radiation into heat. This heat accumulates in the unpaved seasonal heat storage (system of vertical heat exchangers). For your heating and hot water is used directly by the energy-active roof or facade, seasonal ground heat storage or heat pump. Heat pump with a warm seasonal heat storage is working with a large effekt. Sistems can provide a full solar heating (House "0 – energy"). Details on the website http://solar-house.ucoz.com/, have a translator.
    Vitaly Strashko.

    Link to this

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