Should solar initiatives shift from rooftops to solar-farms?

[Dr. John Barnes]

Although CST concentrating solar thermal farms produce the lowest LCOE (levelized cost of energy) with several ~100MW implementations in the planning/approval stage in Southern California with realizable targets of less than $0.09 per Kw/hr, PV solar farm implementations in the range of 1- 20 MWp provide the most viable, fastest to implement, and profitable option for generating massive amount of solar energy at the present time.

These PV farms are small enough to allow connection into power substations and not require building new transmission lines. Building transmission lines across varing municipalities takes many years. In addition they can usually be built in proximity to the sub-station on land that will not require excessive environmental studies, such as that for a 100MW CST plant.

The financial return for such a PV farm is now attractive with the massive drop due to inventory excess in the PV module manufactures world wide. Financially this massive solar generator farm requires only a guarantee of a feed-in tariff, or guarantee of purchase such as now exists in California with PG&E, Southern Power Edison etc. through a minimum PPA agreement fee. Old PPA’s from the largest “solar power providers” such as SunEdison, MMA, Recurrent Energy, Solar Power Assets in California under last year’s federal and state incentives were starting at about $0.15 per KW/hr. It would require less now to make the financials work out for all concerned.

~10MW PV can be be best alternative to meet the requirement of solar to satisfy state reaqirement for ~20% renewable energy in a fast manner. Everything is in place to make this happen.

[Sol Shapiro]

Response to John Barnes:
Your solution sounds like good business. Is it the right public policy for the U.S. long range future?

[Dr. John Barnes]

Sol,
Your question was “Is it the right public policy for the U.S. long range future?”

Yes the best sequencing is first massive PV from 1-20MW solar farms, then the longer term >100MW CST farms in the Southwest, and lastly a natural slower build from commerical installations (~150KWp) and of course individual houses in the 5KWp area. The individual will want to do their part, but making the required quota of >20% from renewables with houses won’t do the job, by a large margin.

Already Germany is finding that some of their local lines can have up to a 80% generation from the PV installed on weekend days. This is a long term problem for distributed PV that is not localized as in the proposed 10MWp solar farms.

[Sol Shapiro]

John,
As I have watched the effects of Amendment 37 in Colorado, I realize that visible pv served to make people aware of the potential for renewable energy.
But in an economic sense, central facilities make much more sense; the quantitative economci saving in transmission does not justify the difference between distributed and central. On the issue of storage I think we should work with cst and even better geothermal which could benefit from the fiscal support going to the distributed to move them along faster. Now pv in areas where there is not grid certainly makes sense; and with the great selling job done by pv and its build up of manufacturing capacity, it may not make sense to shut it down. For it is possible that applications that do not require dispatchable resources will grow; e.g., a hydrogen economy (which I don’t really think will happen) or a if a liquid transportation fuel from electricity were developed, it would make the cost of energy without regard to dispatchability of value. As I have suggested to a number of people, it would not surprise me if the pv industry will follow in the footsteps of the fiber optic industry - overcapacity, bankruptcies and a sharp reduction in cost of energy production resulting from write-off of capital costs.
But I do think that it is cst and geothermal which should be getting the bulk of public policy support today. I think the planned Xcel procurements in solar are along those lines.

[Dr. Rajan Kapur]

Are single family PV installations an impediment to massive deployment?

Single family residential deployment is 20-50% more expensive per kW installed, and it yields 10-20% less kWh per year/per kW installed, compared to larger installations.

It has been an important starting point:
a) Single point of decision, individual is “empowered”
b) Real estate is already “paid for”
c) Generates employment
d) ROI for the industry

Utility scale deployment has begun receiving widespeard attention — it benefits from economies of scale; enables competing, and possibly less expensive technology deployment, and can be optimally sited in high sunlight, low population, low cost land. Germany has started heading in this direction, and policy in the US is also recognizing this.

For Colorado, the Governor’s Energy Office has an excellent report on this
“Connecting Colorado’s Renewable Resources to the Markets” evaluating solar and other sites at
http://www.colorado.gov/energy/index.ph ... lications/

The catch with utility scale deployment is transmission lines for evacuating the power to markets: If lines or capacity don’t exist, it can take 7-10 years to put them in place.

“Wholesale Distributed Generation” can be a nearer term alternative for massive deployment that combines the best of “retail” and “utility scale”.

WDG enables economies of scale, optimization of orientation for power harvest, and local installation (e.g. near substations etc) to avoid transmission line losses and delays.

California has begun taking policy steps to support this: http://docs.cpuc.ca.gov/efile/RULINGS/99105.pdf

Is this the right approach? Should we go further, and reduce subsidies for single family deployment?

[Dr. John Barnes]

Your starting question was: Are single family PV installations an impediment to massive deployment? then you asked if subsidies should be de-emphasized for residential installations to get massive deployment going.

For residential installations a fast decreasing cash payment, with the total money for the program available capped, and steps for payment levels as installations are completed, such as the California Solar Initiative was good to start awareness three years ago. However, you never get to the approaching 33% energy from renewables requirement with these 5kW roof-tops.
I would let such residential programs run their coarse, but don’t renew or up the subsidies here for massive deployment. I don’t think that new subsidies are desired for residential as the iniatial question might ask.

Today (4-23) I listened to the SEPA sponsored Promethius report on the status of solar PV costs and demand for 2009-2010, and it once again showed that the costs of modules, installation costs, and oversupply due to the drop in demand for Spain give us in the US a GOLDEN OPPORTUNITY to move into first place in installed PV. Ideas here by Probir and others give direction for that move.

This needs to happen one investor owned 10 - 20 MWp PV farm at a time and with some utilities such as PG&E going for the 500Wp Topaz farm in San Luis Obispo with First Solar etc.. Today I saw than Sempra was going to go for a new 500 MWp solar farm in AZ.

All things could be alligned with some State PUC help for a known fixed rate for sales to the big utilities. We can’t let the utilities try to only pay rates, like coal generated electricity for the next 5-10 year period. This purchase rate differential, will of coarse be born by the rate payers in the states. That will be the citizen’s clean energy tax and investment burden. It can’t add up to the projected 200-300 euros per year per family that is expected to happen in Germany from their expensive FIT rate for solar, however!

Just a short time of reasonable rate for solar generation like $0.22/kWh which is proposed by some, will allow this massive solar farm effort to mushroom and take the US to the leadership position as the Invvest org desires.

[Dr. Rajan Kapur]

“Every BIG helps”
– David MacKay, Cambridge University

“Setting aggressive renewable energy goals that must be met every two years is a better way to spur innovations than what longer-term goals could accomplish”
– Michael Splinter, Applied Materials

The often cited report from a Task Force orchestrated by the Colorado Governor’s Energy Office, “Connecting Colorado’s Renewable Resources to the Markets”,
http://www.colorado.gov/energy/index.ph ... lications/
(under Reports & Industry Studies) is a comprehensive inventory of BIG renewable energy resources in Colorado.

It identifies “Generation Development Areas”, that have at least 1GW of renewable resources each, and where developers can compete for utility scale projects. It identifies 2 GDAs for Solar, and cites an NREL report that used an arbitrary screen for analytical purposes (not to be construed as an upper limit): just 2% of the identified areas would yield 5.5GW.

The report also identifies 8 GDAs for wind, and inventories hydropower, including pumped storage; geothermal and biomass; and ethanol and biodiesel. It describes the Colorado electricity generation environment with respect to renewables, and the status of transmission capacity. It wraps up with a description of state policy in support of renewables, and current status across IOUs, REAs and municipal utilities in the state.

It posits that Colorado can be a net exporter of renewable energy, based on available natural resources. It identifies barriers for utility scale deployment, and states that perhaps the foremost challenges for wind and others are the unique transmission capacity constraints that exist in Colorado.

Task Force members have submitted the report as a means to encourage further dialogue among all interested stakeholders, to continue discussion on these important topics – the report is unique in its coverage, and an important step towards energy independence.

In this context, we posit that Wholelsale Distributed Generation solar systems can be an adjunct to utility scale GDAs: for local load centers, WDG offers the opportunity to finesse the transmission issue, and facilitate BIG deployment.

Policy activity in support of WDG has begun in California (although John Barnes reports initial comments do not contain tariffs that will encourage massive deployment). Also in California, in Santa Clara, a forward looking county supervisor has proposed WDG for supplying county needs:
http://social.cpvtoday.com/content/sant ... tallations

We are not aware of any inventory of 1MW-10MW opportunities located close to load centers: we encourage stakeholders to discuss means for inventorying this opportunity: while the chatter about community scale and district scale solar deployment is increasing, absent an inventory we can only conjecture that BIG deployment is enabled.

[Probir Ghosh]

Rajan & John,
The opportunity can be seized only if we can have a national level comprehensive policy in place for massive scaling where the industry and the Fed and State work closely together to bring the prices to power parity by 2015 or earlier. Individual State Policies needs to fit under this comprehensive policy.
I would suggest a modified PPA plan that takes into account a 4% power price increase (or an agreed upon power price increase) over the next 20 years and see if the industry can reach a 10 cents per kWh starting point in 2015 for solar farms bigger than 200MW (hence probably needs transmission upgrades& connectivity) .
Where new trasmission lines are not required and we can treat that as distributed power supply, for 1MW - 20MW range, I suggest a modified PPA plan that takes into account a 4% power price increase (or an agreed upon power price increase) over the next 20 years and see if the industry can reach a 12 cents per kWh starting point in 2015.
Our modelling shows that we do not need disruptive technolgies on the flatplate panel side to reach these goals, we will have to stream line BOS significanly from current models. CPV and CST holds promise but needs to be validated with realtime data as the first few installs come on line in the next 12 months or so.

I believe residential rooftops will become a very small protion of total solar intalls as our modelling shows that with current technology roadmaps, we will still need 40 cents plus per kWh to make it economically attractive without incentives in 2015.

This can open up possibilities for disruptive scaling.

It will be nice if we can get validated data for various types of installs from Fixed to 1axis realtime validated data readings as well as validated data of energy production from CPV & CST installs.

We have very specific initiatives and policies in mind that can be discussed among key thought leaders for a disruptive scaling scenario.

[Probir Ghosh]

Does anyone have data on what the cost of pumped storage is?

[Sarah_Kurtz]

Choosing winners can hasten development if we make the right prediction, but can slow development if we make a poor choice (which often happens).
We need to
1. Leave all options open (so provide fair subsidies for all approaches simultaneously - see note #4, below)
2. Make sure that the rate structure (including structure of incentives) mimics the true costs as closely as possible
3. Plan all subsidies to be slowly reduced; as the subsidies are reduced, the market will determine the relative importance of each approach. This is likely to vary with location.
4. Begin a discussion early on about what is (in the context of #1 and #2, above) (a) an incentive that should go away (e.g. rebates for installed PV systems?), (b) an incentive that we decide as a society we want to keep (e.g. public insurance of nuclear plants?), and (c) what is part of our business structure (e.g. depreciation of capital investment and tax write off for costs of permitting?).

Specifically related to rooftop vs solar farms: we should encourage both: the trick is identifying what form the encouragement should take. Can agreeing upon the underlying principles (such as the points above) help lead our decisions?