We are building a new home and are looking at our options in Wind or Solar Power. We are on grid ICF Home with about 1700sqft upstairs and a full unfinished basement. Are there cost effective options out there that we should be looking at? I am not sure where I should be even starting? Solar or Wind? The house is located in the Bloomington, IL area. Bloomington is known for their huge Wind Farm.

petrey10-

Download a free copy of PVWatts to evaluate the solar PV potential. PVWatts Version 1 is easier to use, but PVWatts Version 2 is more accurate in defining the solar energy at a particular location if your location does not correspond to one that is listed in PVWatts V1. Probably start with Version 1. My experience, with results posted on my website, is that PVWatts significantly underpredicts the actual power that is generated.

Wind generators often run into zoning and/or deed restrictions. You might check those before considering that route. I do not know of a good tool to evaluate wind energy potential of a site, and it certainly will be site specific, and height specific. (I know that in the Texas panhandle, they discovered that very tall commercial towers, I think over 75 m, could pick up a nocturnal wind not available at lower altitudes. Presumably you'll be lower, but still subject to local variations.) Wind generators have moving parts that are subject to damage, where solar PV does not have moving parts, but panels are subject to hail damage.

In very large sizes, wind generators have cost advantages relative to solar PV, but my guess is that in small sizes that is reversed, i.e., solar PV has the advantage. You should also check federal tax rebates and local utility rebates and policies for buy-back and subsidies.

Lee Dodge
www.ResidentialEnergyLaboratory.com
in a net-zero source energy modified production house

What are your goals and what is your definition of "cost effective"?

Self-sufficiency?
Maximizing power generation per dollar of expense?
Quickest payback time?
Greenest solution?

At this stage of the game, PV power can be very much set up and forget, while wind will require a bit more attention and tinkering from the homeowner.

Looking to lower the monthly payment on my electricity bill since my house will be all electric except for the fireplaces....

Quickest payback time would be nice..

located in East Central IL

I figured that the payback time for my 3.15 kW solar PV system in my sunny location will be 7 years if I were using all the electricity that it produces. It was sized for net-zero source energy, providing all electricity that the house uses, plus offsetting natural gas used for heating, but that oversizing results in a longer payback time. The electrical utility sells at the retail rate ($0.10/kWh), but buys excess at the wholesale rate ($0.03/kWh). That payback time includes the significant rebates from federal taxes plus the local utility. Again, using PVWatts plus an estimate of your electrical usage would help you evaluate a solar PV system.

Looking to lower the monthly payment on my electricity bill since my house will be all electric except for the fireplaces....

Quality construction
Air sealing to prevent infiltration and control air exchange
Upgrading insulation
Attention to passive solar principles

All these things reduce energy use in the first place before looking to supplement it.

If you heat with electric, it needs to be something efficient like an air source or geothermal heat pump.

the payback time for my 3.15 kW solar PV system in my sunny location will be 7 years

Lee, have you calculated an "average" number of hours per day that your system generates (full) output at your location?

ICFHybrid-

I don't think the average number of hours per day that I am at full output is a useful metric. However, I have generated 7386 kWh over 450 days, so that would work out to 2345 hrs for a 3.15 kW system, or 5.2 hours per day at rated power. (That includes more summer days than winter days, since the system was installed in May, so annual average would be a little less, maybe 5 hours per day.)

A more useful metric for comparing solar systems is to look at average solar insolation, using a web site such as http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/serve.cgi. The average annual solar insolation at my site on a panel aimed south and tilted at the latitude is 5.9 kW/m^2/day. My panels are tilted up at a lower angle than the latitude, and that reduces the average to 5.8 kW/m^2/day, still an excellent value. For folks to estimate solar PV system performance at their location, simply go to that website, input your own location, and see what your annual solar insolation is. Then you can take my system performance, 5910 kWh per year, and multiple it by the ratio of the solar insolation at your location to the solar insolation at my location. For example, if the annual solar insolation at your location on the flat plate tilted at the latitude is 5.0 kW/m^2/day, then you could expect about 5910 kWh x 5.0/5.8 = 5095 kWh for a 3.15 kW system. The amount of power is proportional to system size rating, so if you need to generate 10000 kWh annually, then you would need a system size of 3.15 kW x 10000/5095 = 6.16 kW rated system. To be more accurate, you could account for solar insolation as well as different angle mountings using the computer model PVWatts.

To compute payoff periods, you need to factor in your electric rate. Mine is $0.10/kWh. And you need to estimate energy inflation rate. I estimated 4.7% per year based on the natural gas inflation rate in Colorado over the last 22 years.

Unless the house is at the top of a hill odds are you'd have to build a fairly substantial tower to make wind a viable option- it'll likely cost more up front, and will have higher maintenance costs than PV. Where subsidies and un-shaded exposure are available (along with net-metering at retail) PV can have a reasonable return, but un-subsidized and metered at wholesale it's a pretty tough argument at current PV costs.

But designing the roof pitches & exposure (or even pre-wiring) for solar is still a good long-term plan on new housing, since PV costs have fallen dramatically over the past decade, and are expected to fall even further. At some point in the next couple of decades the financial argument is likely to become compelling. Panels are still the lions share of the upfront cost, but those costs are crashing. There is progress being made on the "rest of system" (inverters, etc) costs as well, but that portion is on a different price tragectory, and will probably become the bigger fraction before 2020 (maybe even by 2015).

Efficiency & conservation are still by far the better value. Designing it for high efficiency lighting such as linear T5 or T8 fluorescent with dimmable ballasts and/or occumpancy sensor controlled can help. But start by actually DESIGNING the lighting rather than letting your electrician pound in a sea of recessed cans and calling it a day counts for a lot. High-efficiency up-lighting coves/valances for the primary ambient lighting results in lower glare, which give better visual acuity even at lower luminosity. Downlighting is high glare, and casts shadows on your work if not placed correctly. Self-ballasted CFLs & LEDs are great & all but still barely more than half the efficiency of T5 (5/8" diameter) fluorescent tubes. You can buy & install a lot of dimmable fluorescent & occupancy sensor control technology for the cost of 1KW of PV. With some design & forethought you get BETTER lighting in a home, while cutting the power expenditure by 90% from incandescent lighting (or half the power use of cheap CFL/LED technology.)

Getting rid of background "phantom loads" of chargers & appliance power supplies that draw power even when "off" counts as well, but takes some investigation to track down. Managing the plug-loads well is often the make-it-or-break-it on cutting power use.

Even with heat pump technology heating, if you're looking for near-net-zero with PV technology, bumping whole-wall R values to at least R30 (or even R40) makes sense in Bloomingtion IL. If you take the R10/R20/R40/R80 approach to basement-slab/foundation-wall/above grade wall/attic whole-assembly R-values you can get close in that climate, especially if you tune the passive solar aspects a bit. But even without net-zero-energy as goal R8/R15/R30/R65 makes some economic sense as a rough guide depending on how you go about achieveing those values (clearly the payback on R65 attic is "never", if done as closed cell spray foam). As a rough guide, see table 2 on p10 of this document:

http://www.buildingscience.com/documents/reports/rr-1005-building-america-high-r-value-high-performance-residential-buildings-all-climate-zones

(Bloomington is in climate zone 5.)

Dana1 states: "Where subsidies and un-shaded exposure are available (along with net-metering at retail) PV can have a reasonable return, but un-subsidized and metered at wholesale it's a pretty tough argument at current PV costs." "Efficiency & conservation are still by far the better value."

I have come to a different conclusion for my particular house and location (sunny climate zone 6), which has net metering at wholesale electric costs. Payback for solar PV was 7 years if my system were not oversized relative to my needs. Payback for solar hot water is hard to estimate, but I have computed 26 years. In contrast, payback for adding insulation beyond code minimums was longer term. Payback to upgrade the attic insulation from R-38 to R-60 using cellulose was 28 years. Payback for adding 2" of XPS insulation to the 2"x6" walls already filled with insulation was 42 years. Upgrading crawl space walls from R-14 to R-19 was 29 years. All of these costs were based on professionally installed systems, not DIY, and all were based on modifications to design of a house under construction, so no tear-out and replace. Actual costs are provided at http://www.residentialenergylaboratory.com/costs.html.

I do agree with Dana1 about the advantages of fluorescent lighting, although CFL's are easier include in current lighting considered fashionable than tube-type fluorescents. I agree with the idea avoiding recessed cannister lights that correspond to poking holes in your air and thermal barrier.

Lee- you took a HUGE subsidy on this system if you only paid $5451 (after rebates, per your website) for a 3.15kw system. Paying full retail for the goods you 'd be into it for 3-4x that kind of money, with a much longer time horizon on "payback".

Dana1-

Yes, the subsidies that are currently available make solar PV, and, in some cases, solar hot water VERY ATTRACTIVE financially. I will not apologize for the fact that I am using subsidized prices -- they are the current reality of the marketplace. I am also paying huge subsidies for imported oil, namely 2 1/2 wars plus oil depletion allowance, intangible drilling and development costs, and a host of other oil subsiidies. I am also asked to approve of Haliburton using toxic chemicals that they refuse to disclose as they drill and "frack" for natural gas. Other people are paying for subsidized oil with their lives.

But I would encourage folks to take advantage of solar systems right now. In my area, the local electric utility will be rolling back their subsidy as they meet the state-mandated requirements for renewable energy. Since we are not making any more oil, I doubt that the price will drop over the long term.

As stated on my website, the unsubsidized cost last year for my PV system was $18337, but with federal and utility subsidies, that was reduced to $5451. So your advice needs to be adjusted for the reality of what systems cost people today. Local subsiidies are variable, but the federal subsidy is universal in the U.S. In some cases, especially sunny climates that have utilities subsidizing solar, investing in solar is far better than adding insulation beyond code minimums. In my case, I invested in both. Getting electric bills that consist of just the connection fee of $7.40 each month, and maximum natural gas bills of $47 per month (including $11 just for connection fee) in climate zone 6 makes me feel good about the investment.

Some good info there. It's probably in there somewhere, but how were you calculating the projected savings per year for each feature?

jonr-

Thanks. You have spotted a deficiency in the web site that will be addressed in the future. I have not given you any clue as to how the energy savings are calculated. The savings for added insulation are straightforward, and hopefully accurate. I have used RESCHECK, which is available for free. I have entered the description for house with the insulation levels as they exist in the house. I run RESCHECK and it provides a result for the thermal conductivity of each piece of the house times the area of that piece, which it labels UA, which is the U-factor for each element times the area A for each element, and this product summed for all elements. Then you multiply UA times the heating degree days converted to hours and you get the Btu required to heat the house through one heating season, accounting only for thermal conductivity, (ignoring solar and other gains). Then go back to RESFEN and change the single insulation value in question, say attic insulation from R-38 to R-60, get a revised value of UA for the house, mutiply by degree days to get the Btu's required to heat the house with that lower insulation value. Take the difference in Btu's between these two calculations, and divide that difference by the product of the energy content of the fuel times the heating efficiency, to get the quantity of the fuel required to cover the lower insulation level. Multiply that by the fuel cost and you have the cost savings the first year. Then I put that in a spread sheet with an estimated fuel inflation rate of 4.7% per year to see how long it took to pay back the investment, not accounting for the interest on the money if I put it in the bank instead.

So, for example, my baseline house has a UA from RESCHECK of 160 Btu/(hr F), and this becomes 176 Btu/(hr F) if I reduce the attic insulation from R-60 to R-38. Average heating degree days are 7317 days deg F, and when I go through all that I estimate that I save $21 the first year, and a little more each following year, and after 28 years the total $1120 for the extra cellulose and installation costs are paid off.

Some deficiencies of this approach include the following. RESCHECK does not include heat losses to the ground, so no accounting is provided for insulation under the crawl space. If added insulation reduces air infiltration, that is not accounted for. Solar gains due to changes in window characteristics are not accounted for in RESCHECK. Those were estimated using RESFEN.

Thanks for the explanation. I would make it clear on the web site that the payback values are only valid with your climate and fuel costs. I'll guess that increases in fuel cost are about canceled out by the cost to borrow money.

Posted By Lee Dodge on 11 Aug 2011 02:20 PM
Dana1-

Yes, the subsidies that are currently available make solar PV, and, in some cases, solar hot water VERY ATTRACTIVE financially. I will not apologize for the fact that I am using subsidized prices -- they are the current reality of the marketplace. I am also paying huge subsidies for imported oil, namely 2 1/2 wars plus oil depletion allowance, intangible drilling and development costs, and a host of other oil subsiidies. I am also asked to approve of Haliburton using toxic chemicals that they refuse to disclose as they drill and "frack" for natural gas. Other people are paying for subsidized oil with their lives.

But I would encourage folks to take advantage of solar systems right now. In my area, the local electric utility will be rolling back their subsidy as they meet the state-mandated requirements for renewable energy. Since we are not making any more oil, I doubt that the price will drop over the long term.

As stated on my website, the unsubsidized cost last year for my PV system was $18337, but with federal and utility subsidies, that was reduced to $5451. So your advice needs to be adjusted for the reality of what systems cost people today. Local subsiidies are variable, but the federal subsidy is universal in the U.S. In some cases, especially sunny climates that have utilities subsidizing solar, investing in solar is far better than adding insulation beyond code minimums. In my case, I invested in both. Getting electric bills that consist of just the connection fee of $7.40 each month, and maximum natural gas bills of $47 per month (including $11 just for connection fee) in climate zone 6 makes me feel good about the investment.

My advice was predicated upon "Where subsidies are available..."  without presumption, so where's the need for adjusting my advice?  Your situation is EXACTLY what I was referring to with that conditional statement.

The reality is, not everybody in the US is eligible for a US federal tax credit, not every reader of this forum lives in the US, and all subsidies are a moving target.  My advice on PV was to design the house with PV in mind, with the presumption that subsidy or not, the numbers would become compelling at some point. (And with subsidy that point might be now, but I wouldn't presume that.)

Insulation well beyond code min is also subsidized in many areas.  In some places it's as high as 75% (usually only in retrofits) as is the case in a project in MA I'm advising on currently. (On this project a post-subsidy expenditure of 5 grand blows away the ROI of PV at local subsidy levels, and this is 18cent/kwh country, with net-metering available.  It'll be just shy of R60 on the roof, R30-ish for whole-wall R, R15 on the foundation walls, R12 under the slab, heating & cooling with air-source split systems.)  And that's reality too. 

If you're going to use subsidized numbers to make the case, you have to include all available subsidies on the other aspects as well.  Subsidies distort the market- what makes the most financial sense will depend the level of local subsidy. 

The BSC guidelines on R value don't presume subsidy, only the real capital costs and reasonable expectations of (what are spelled out to be very) long term returns. (Read the document.)  Using the rough guidelines as outlined by Building Science Corporations RR-1005 document doesn't imply that those levels are going to have a short term return, or that they will have ANY return if done in a more-expensive manner.  Those levels of insulation done  using resonably cost effective methods (unsubsidized),  means going a whole lot further has an implied assumption that future energy costs will be more expensive than kwh/COP using current PV + heat-pump (unsubsidized) costs & efficiencies.  In some cases going further will make financial sense, in others going that far won't, depending on local utility/energy costs.

When looking at the (again, unsubsidized) cost of a ground source heat pump heating system (as I believe is the case here) there's some immediate payback on higher than code-min R in reduced system size that can be balanced. The "return" of higher-R envelopes isn't  on energy cost savings alone, especially when we're talking more-expensive types of mechanical systems.  Again, the simple-math argument for geo goes away in many cases when the subsidy is removed.

jonr-

You said: "I would make it clear on the web site that the payback values are only valid with your climate and fuel costs."
Yes, that is certainly my opinion, that rather than taking my results, folks need to do calculations for their own climates and circumstances. This also applies to "rule of thumb" advice given by others. The calculations can be done using software developed by Dept. of Energy (DOE) Lawrence Berkeley National Lab. (LBNL) and the National Renewable Energy Labs (NREL) and available for free, namely, RESCHECK for evaluating insulation levels, RESFEN for evaluating the effect of window specifications such as solar heat gain coefficients (SHGC) and U-factor, and PVWATTS for evaluating solar PV. I will try to add more details to my web site documenting exactly these procedures with examples. I will add a note to my website that the payback periods are for my specific circumstances.

As an example of how variable energy conservation practices are with location, I added a south-facing window to the standard design of my production house to increase solar heating, while other people suggest taking out wndows to reduce heat losses (bad advice in some sunny, cold locations).

And you said "I'll guess that increases in fuel cost are about canceled out by the cost to borrow money." That might be true if the money must be borrowed. The cost of energy has been rising at a faster rate than measures of the general inflation rate over the last 10 or 15 years. In my case, I have a loan on a portion of the house at 3%, and money in the bank to pay off that loan at 1%, so I'll split the difference at 2% and factor that in to the return on investment (ROI).

Dana1-

For folks building new houses, I don't know of subsidies for increased insulation levels, at least in my area (Colorado). I did account for all the subsidies that I could find for the changes that I made to improve energy efficiency of the new house, essentially none except for the solar stuff, with the exception of the insulating shades. I will adjust my calculations for the insulating shades, but I ran out of that subsidy since it is limited to $1500(?), and I had already taken about one-half of that for a previous house. A key feature for the solar PV, solar thermal, and wind federal credits is that they have much higher and separate limits from the general federal energy conservation credit. And I think that every U.S. citizen can take things like the solar PV and wind credits, even if they pay no taxes they get a check in the mail. The Canadians cannot take a U.S. tax credit, but at least some areas in Canada seem to subsidize energy from solar PV at VERY high rates. (On this forum some Canadian was mentioning selling energy to their utility at somethiong greater than $0.40 per kWh!)

I have nothing against lots of insulation. I voted with my pocketbook at R-60 in the attic, R-27 in the walls, R-19 on the crawl space walls, and even XPS under the crawlspace, something that I have never heard of anyone else doing. But in building new homes in some areas of the U.S., it will pay off more quickly to add solar features such as passive heating with expanded-area, high SHGC glazing to the south, and solar PV. I would suggest that folks need to do their own homework for their own climate, but don't jump too quickly on the mantra that states "super-insulate first, solar second." It was not accurate in my case.

Lee- Petrey10's current plan (See: http://www.greenbuildingtalk.com/Forums/tabid/53/aff/14/aft/78907/afv/topic/Default.aspx ) is to build with R20 ICFs + geothermal ( subsidised), which isn't exactly superinsulation. Even subsidized on the geo un-subsidized there's probably still an argument to be made for either higher-R assemblies /lower U-glazing to bring the cost of the geo down a well as the peak load. R20 is close to an ICF minimum- the up-charge for another R4-R6 may not be very substantial when factored against the smaller geothermal size/cost.

We're in accord about optimizing the design for passive solar, which has very low up front costs. Whether it's PV now or PV later will depend entirely on his available subsidy & net-metering particulars, but to be sure designing the orientation & roof pitches for optimal PV output should be a part of any new-construction. Anything he can do now to ease installation and optimize performance will be cheaper if designed in ahead of time. If the installed cost after subsidy is under $2K/kw (as in your case) the financial arguments for PV get pretty easy. If net metered at retail there's probably an argument for 2x your array size to better support heating with a heat pump, but making all the right tradeoffs could take a fairly complicated financial model (not just an energy-use model.)

I would suggest that folks need to do their own homework for their own climate

I agree that this needs to be stressed. People like to summarize and simplify and you wouldn't want someone to conclude something generic like "R50 in the attic doesn't pay off". Lots of people ask questions here like "should I go with R20 in the ... or ...". Anything that helps people do it right (like software simulations) is a big plus.

It's good news that PV solar + heat pumps are getting closer to the cost effectiveness of fossil fuels.

where is the best place to buy the panels and all the needed pieces for a PV solar system?

The panels won't be on the actual house but a 2 car detached garage that has 24'x12 side of the roof facing south