Archive for solar energy

Can the Poor Afford a Community Solar Garden Subscription?

Yesterday, I wrote about Community Solar Gardens (CSGs) and their uses from an investment perspective. One of the goals of CSG legislation is to allow people without access to large amounts of credit the opportunity to invest in solar. Yet there is a clause in the bill that places the size of the smallest allowable CSG subscription at 1kW. A typical home system is usually between 2kW and 10kW, so a 1kW system does not seem unreasonable if the intent is to simulate a home system. However, if the intent is to allow people of all economic means to participate, the 1kW minimum may be onerous.

According to Rick Coen, Director of Engineering at Colorado solar installer Bella Energy, a 1 kW solar garden subscription would probably cost about $2,500 after current Colorado incentives and federal tax credits. Colorado incentives have been dropping quickly recently, as have solar panel prices, so this cost could either rise or fall, depending on which falls faster. Nevertheless, $2,500 seems like more money than most typical low income earners are likely to have at one time, so the minimum subscription may present a barrier.

A bill that was designed to allow low income earners to participate would either remove the 1 kW minimum, or provide for some type of monthly payment plan.


The Community Solar Gardens bill (HB1342) does allow the developer of the CSG to provide financing to subscribers, but for someone with low income, such loans would likely need to be secured against the subscription itself in order to achieve a low interest rate. If the income from the subscription came close to covering the payments on the loan, a CSG developer could package together a CSG subscription and a loan so that a 1 kW subscription could be bought on a monthly payment plan.

In sunny Colorado, solar farms often have capacity factors as high as 20%. At that capacity factor, typical monthly production for a 1kW nameplate system would be 146 kWh, which is worth about $14.60 a month at typical Colorado residential rates of 10 cents per kWh. Using a mortgage calculator, I found that the income from the subscription would be enough to pay off a $1,400 ten-year loan at 5%, an $1,800 fifteen-year loan at 5%, or a $2,200 20 year loan at 5%. That means that with $300 down, a low income subscriber could pledge the income from the CSG subscription for 20 years, and would eventually be able to use the income from it after the loan was paid off 20 years later. Solar panels can last for well over 20 years, so the subscription could still be worth something at that time.

A more likely option would be for the subscriber to make the initial $300 down payment on the 20 year plan, followed by smaller amounts each month to accelerate the debt repayment, and end up owning the subscription outright sooner.

Despite the potentially daunting $2,500 initial cost of a 1kW subscription, it looks as if developer financing could bring this down to a manageable initial payment. All of this assumes that incentives for solar do not fall faster than the price of solar installations, and that currently low interest rates stay low. On the other hand, if electric rates rise, the income from a CSG subscription might be enough to cover the entire subscription.

Truly Affordable Solar

While financing can in principle allow the low income earners to purchase a Community Solar Garden subscription, it remains to be seen if there will be enough demand for an asset that has no tangible value for twenty years among people without much cash to spare. I doubt that the demand will be sufficient to entice a CSG developer to offer such a complex financing arrangement. A much simpler way to make CSG subscriptions affordable would be to allow subscriptions smaller than 1 kW.

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Community Solar Gardens

A new bill being considered in the Colorado legislature would create "Solar Gardens." Solar Gardens allow people to participate financially in owning part of a solar array even if they do not have a suitable site on their own property. My reading of the proposed legislation is that subscriptions in a Solar Garden would be financial securities, and fall under securities laws. That’s probably a good thing.

Solar for Everyone

Solar panels are elitist: They cost a lot of money, and only homeowners with good solar access can usefully install them. This means that renters and people who can’t come up with at least $5,000 to $10,000 worth of cash or credit can’t own them. That’s the problem Colorado House Bill 10-1342 (HB1342): Community Solar Gardens aims to correct.

HB1342 defines a Community Solar Garden(CSG) as "A solar electric generation facility with a nameplate rating of two megawatts or less… where the beneficial use of the electricity generated by the facility belongs to the subscribers to the community solar garden." A subscriber is a "retail customer of a qualifying retail utility who owns a subscription and who has identified one or more physical locations to which to which the subscription shall be attributed" withing the same county or municipality as the CSG. The bill allows subscribers to change the premises to which a subscription is attributed, and also to sell them to other qualifying subscribers, something which is necessary in case a subscriber were to move out of the county or the utility’s territory.

It’s a worthy idea, although local solar installers are concerned that the superior economics of large installations will eat into their market share, by easing the requirements in House Bill 10-1001 for customer-sited generation. People who own perfectly good sites for rooftop solar may instead choose to buy a CSG subscription because of the convenience and potentially lower price. I think fears that residential customers who are good candidates for rooftop solar might instead subscribe to CSGs are overblown. Although the economics may be better, buying solar in Colorado is not yet a great investment because of the cost an return involved. Instead, I believe people are investing in solar because it gives them satisfaction to think that they are using green energy, and because they want to show off their environmental bling to their neighbors. I know that some people are more interested in the bling aspects of solar panels than the economic aspects, because otherwise there would not be a market for fake panels in Japan, although I don’t know of anyone who knowingly bought fake solar panels in the US.

On the other hand, there is currently a multiplier in the bill which would allow 2 kW of CSG subscriptions to substitute for 3 kW of rooftop solar that I think needs to be fixed to avoid undermining the residential set-aside of Colorado’s renewable energy standard as envisioned in HB 1001.

Energy Sprawl

My greatest concern with the bill is not that it will cause a move towards large installations, but that it will lead to more ground-mounted installations taking up open space, contributing to Energy Sprawl. No matter what you think about the economics of photvoltaics, one advantage that they have over almost every other type of electricity generation (both fossil and renewable) is that they can be placed on otherwise unused rooftops and other structures, giving a use to otherwise wasted space. Only energy efficiency and conservation have less physical impact on the environment than rooftop solar. Some people have told me that their air conditioner ran less after they put solar on their roof.

Any law which makes solar more likely to be ground-mounted than rooftop is a step in the wrong direction. I think the bill should be amended to prohibit CSGs from being ground-mounted, effectively limiting them to large rooftops and other structures such as awnings for parking lots. This would also have the effect of doing something to limit the practical size of CSGs to available rooftops, which would probably make the solar installers a bit happier.

The Secondary Market for Community Solar Garden Subscriptions

Provisions for a secondary market for CSG subscriptions are included in the bill, since a subscriber moving out of the county in which their CSG is located will not be able to benefit from their subscription. The secondary market and and other security-like characteristics of subscriptions may make them a useful financial tool for small investors. Most importantly, a CSG subscription is (as intended) an excellent hedge against rising electricity prices.

The only real reason to hold a CSG subscription for the long term is as a hedge against rising electricity prices because, like all utility-subsidized solar installations in Colorado, the utility ends up owning the Renewable Energy Credits (RECs), which are defined as all the “environmental attributes of the electricity.” Although most people with solar panels don’t understand this, the fact that they cannot legally claim the RECs means that they are using electricity that is just as dirty as any other Coloradan, with the exception of direct purchasers of RECs or Carbon Offsets, such as Windsource or Colorado Carbon Fund subscribers.

Although the secondary market for CSG subscriptions is likely to be very illiquid, it will probably become a good direct indicator of local expectations for utility rates. CSGs will not be much use to speculators, however, because there are restrictions in the bill which limit the investment to only 120% of estimated electricity usage at the designated physical location of the subscription. Nevertheless, experienced local market professionals with an understanding of market psychology may be able to make small profits trading subscriptions, since the illiquid and unprofessional nature of the market will likely make prices extremely volatile and subject to strong behavioral biases. When electricity rates are rising, subscription prices will likely overshoot their true value as potential subscribers overestimate future increases, and prices will likely undershoot if falling natural gas prices lead to falling interest in CSG subscriptions.

Allowing investors into the subscription market would probably create a more liquid and stable market for subscriptions, but such an outcome is unlikely because of the general public distaste for speculators. It’s also impractical because of the fact that payments to subscribers are at the retail electricity rate, which is considerably higher than the owners of commercial solar farms are allowed, and hence are effectively subsidized by all utility customers, over and above the direct subsidies given to encourage solar in Colorado.

CSG subscriptions have other aspects that will be familiar to investors. The law allows for the CSG to finance the purchase of a subscription (buying on margin.) It also allows the payments for electricity production to either go to offset the subscriber’s electricity bill, or to go to the CSG sponsor. In the latter case, I could see a small subscriber buying a small subscription, and enrolling in the equivalent of a Dividend Reinvestment Plan (DRIP): rather than cash payments, the electricity generation would be used to increase the size of the CSG subscription over time, until the subscriber decided to start taking cash payments. A CSG with a large number of subscribers enrolled in DRIP-like plans might add a new solar module to the farm every month, in order to keep up with the growing subscriber base.

CSG subscriptions could become a valuable financial planning tool for retirees and others on fixed incomes. Because a CSG subscription rises in value with utility rates, an owner would be better able to budget for the utility bill, no matter how wildly electricity prices gyrate. As subscription prices fall with the falling cost of photovoltaics, I can see the purchase of a CSG subscription becoming standard financial advice for retirees.

CSG Subscriptions as Securities

Although professional investors and speculators will have at most a limited role in the trading of subscriptions, CSG subscriptions may legally be securities. The legal definition of a "Security" is an investment in an enterprise with the expectation of profit from the efforts of other people. If I’m right and the draft law is not changed, CSG subscriptions will fall under Colorado securities regulations. (Because CSG subscriptions cannot be sold outside the state, they are clearly matter for Colorado security regulators.)

For small CSGs set up by community organizations, this is unlikely to have a tremendous impact, because securities laws include a number of exemptions for sales to a small number of related individuals. (Note that this is not intended as legal advice! I am not qualified to give legal advice, and even a small CSG should need to consult with someone familiar with the relevant laws.) For large CSGs with many subscribers, securities law may actually require the delivery of a prospectus and fall under a variety of other rules about communications that apply to the CSG developer and its representatives. In general, this is probably a good thing, since it provides a strong legal framework under which regulators will be able to sanction unscrupulous CSR developers who might be tempted to cold-call unsophisticated utility customers and over-promise the benefits of a small subscription in a Solar Garden.


The intent of Community Solar Gardens is a good one, because it allows many more people the opportunity to hedge their electricity price risk. The people in most need of such a price hedge, those living on small fixed incomes, generally do not have both the home ownership and credit that installing a solar system requires. So I’m glad to see Colorado pioneering this concept, and it will be very interesting to see how CSGs and the market for their subscriptions evolve when the final bill passes. With luck, and a few people emailing Claire Levy, the bill’s sponsor, that final bill will have been amended to exclude ground-mounted Community Solar Gardens, and help preserve Colorado open space.

I also hope that some among the majority of my readers who are not in Colorado will suggest your own legislators consider local variations of this idea.

Tom Konrad PhD CFA

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Is There a Tradeoff Between Economics and the Environment?

Tom Konrad Ph.D.

California’s RETI process lends insight into the near-term prospects of Solar, Wind, Geothermal, and Biomass.  

In September, California’s Renewable Energy Transmission Initiative (RETI) released their Phase 2A report, which outlined potential transmission corridors to collect renewable energy from Competitive Renewable Energy Zones (CREZ) that had been identified in previous phases.  As part of Phase 2A, they also screened each CREZ for environmental impact, and the potential difficulty of obtaining land for renewable energy development.  

I previously looked at the results from Phase 1A and gained some insight into the cost of renewable energy technologies.  However, what renewable energy projects actually get built has to do with a lot more than just economics.  If it raises too many environmental concerns, such as infringing on endangered Mojave Ground Squirrel habitat, it isn’t going to get built.

Drawing on the spreadsheet "Supplemental Materials, CREZ Data" I put together the following charts, graphing the economics of each type of renewable energy in each CREZ against the expected environmental impact of that CREZ.  

Each circle represents one type of renewable energy at one of 35 CREZs.  Concentric circles in different colors appear where a single CREZ offers multiple types of renewable energy development.  The only difference between the two graphs is the size of the circles.  In the first graph, circle sizes represent the potential annual energy production (GWh/yr) of a CREZ, while circle sizes in the second shows power rating (MW.)  Geothermal and Biomass resources are relatively larger in the first graph because these are typically baseload technologies generating electricity near peak capacity all the time, while solar and wind are variable.

The cluster of circles in the middle right represent resources outside California: they were not rated for environmental concerns, so I assigned them an arbitrary value in the middle of the range in order to display them on the charts.

Economic/Environmental Tradeoff?

I found it surprising that there is little evidence of a tradeoff between economic viability of CREZ’s and environmental impact.  In fact, the circles in the graphs above are generally clustered along a line from the lower left (high environmental impact, bad economics) to the upper right (little environmental impact, good economics).  A tradeoff between economic viability and environmental concerns would manifest itself in a clustering along a line from the upper left (bad economics, little environmental impact) to the lower right (good economics, large environmental impact.)

Considering these four major renewable energy technologies, as they might be deployed in California, there is no real tradeoff between economics and the environment.  The best economics coincide with the least environmental impact.  If we were to include energy efficiency in the analysis, the trend would be even more pronounced: energy efficiency has the best economic profile of all, yet avoids the use of energy and hence does less harm to the environment.

The exception here is biomass.  The small green dots don’t show a pronounced trend in any direction, meaning that there may be some tradeoff for biomass.  Such a tradeoff would not be surprising, because harvesting plant matter on a large scale is bound to have significant ecosystem impacts.  Note that Biomass here does not include such technologies as waste to energy, which can be environmentally benign, or even an improvement compared to land filling.  In this study, the biomass in remote regions that do not yet have transmission, since lack of sufficient transmission was one of the requirements to be a CREZ.

With clean energy, it may actually be possible to do well while doing good.

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Solar Stocks

In May, I went to Solar 2009.

One panel I attended led to a series of articles on Solar stocks:

  • The outlook for solar stocks
  • Why First Solar (FSLR) is a risky bet.
  • Why Solar Millenium may have what it takes.
  • I also particpated, with presentations on the best incentives for solar investments, and with an analysis of large scale electricity storage, as well as alternative renewable electricity integration strategies.

    Charles also attended, and took a look at the implications of the removal of the $2000 cap on the residential Investment Tax Credit.

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    Concentrating Solar Power: An In-Depth Look

    I recently interviewed several industry participants and research scientists about Concentrating Solar Power (CSP) and associated thermal storage. 
    Several articles came out of these interviews:

    Why Concentrating Solar Power Should not Try to be Coal

    The Solar Projects that Won’t be Built

    What the Future of Concentrated Solar Power Might Look Like (This one made the folks at Ausra uncomfortable, and so they asked to respond.)

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    Transport Fuels and Solar Technologies: Bird’s Eye View

    For my last couple AltEnergyStocks Columns, I’ve been taking a step back and looking at how we can get an understanding of the broad trends of energy technologies. Last week, I added to the Visual comparison of Electricity Generation Technologies I did last spring with a new Visual Comparison of Transport Fuels.

    Following up, today I published a look at the varius solar technologies through the lens of their applications.

    Before we go back to looking at trees, I hope you enjoy this look at the forest.

    (and don’t miss the National Tour of Solar Homes next Saturday)

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    Denver Tour of Solar Homes Sneak Peak; links to National Tour

    Preview the Denver Tour of Solar Homes Online

    The Denver area Tour of Solar Homes takes place in less than a month, and this year you can preview some of the buildings involved online. 
    Check out the Sneak Preview on the right-hand side of the
    Tour of Solar Homes page on the CRES Web site



    The 2007 Tour of Solar Homes will take place on Saturday, October 6 in Denver and most locations around the state.  However, some of the activities are slightly different. 
    The Boulder tour will take place on Saturday, September 30. 
    And the tour in Pueblo will span two days: October 6 – 7. 
    See a complete listing of solar home tours in Colorado on the American Solar Energy Society Web site.


    National Solar Tour


    Outside of Colorado, people you can find tour in your own community by visiting the National Solar Home Tour website.


    Volunteers Needed for the Tour of Solar Homes October 6

    CRES needs volunteers to help with the Denver Metro-Area Tour of Solar Homes on Saturday, October 6.  If you step forward, you will assist homeowner with visitors.   

    There are two shifts: morning from 8:30 a.m. to 12:30 p.m., and afternoon from noon to 4 p.m.  

    Volunteers are welcome to spend the half-day they are not working touring homes themselves. Volunteers are also invited to attend a workshop free of charge from 6 – 8 p.m. Thursday, Oct. 4 titled "Solar Photovoltaics and Xcel Energy’s Solar Rewards Program" and presented by Jeff Scott of SolSource and Juliea Gauthier of Xcel Energy.  The
    workshops take place at the National Renewable Energy Laboratory (NREL) Visitor’s Center at 15013 Denver West Parkway in Golden, which is two blocks west of the Denver West Marriott at I-70 and Denver West.

    Following the workshop, veteran volunteer John Avenson will give a brief orientation for volunteers about the duties the day of the
    Tour of Solar Homes
    . To volunteer, contact Patty Roberts via email at: patty at pacificmillimeter dot com

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