- Email: [email protected]
Prospects for solar thermal electricity generation — an introduction
Solar Energy Materials
Sol:tr Energy Materials 24 (1091) 78-81 Nolh-Holland
Prospects for solar thermal electricity generation an introduction Pascal D e L a q u i ! Renewable ~nerg?; Manager, Bechtel Group Inc., 50 Beale Street, San Francisco. CA 94105, US,4
1. httroduetion The future potential for solar thermal electric power plants is quite significant. The size of the renewable energy resource ba~,e for the U n i t e d States of A m e r i c a alone is almost 500 time~ its current p r i ~ a r y energ'~" consumption._ _. Unfortunately, the levels of curren~ utilization are ,.~uite small. Why have these technologies not m a d e a la~'g,:r c~.::a,nbution to today's market" The answer is that significant barriers still exist. Tb,. most importz:U of the~e a,_'e: (1) The current econo:ruc cll.,,,:~, of low fuel prices. As the recent events in the Middle Fast show .~nce , ~ , m , this m a y change veu, rap!dly. (2) The ct, rrent er~ergy market, as well as ~.he financial community, is insensitive to the social ~iid enviror.mental benefits of renewable energy s~ources. The converse of this is that the social and e n v i r o n m e n t a l , . ~t., of ,~,~,, , ~ , , u~c ai.~ . u t o~.,,~ accounted for in ~he market place. Estimates of the ~OCl.~ - " ' 'and environmental costs of electricity production from fossil fuels range from 2 to 6 ¢,/kWh. [1.2]. Unfortunately, no mechanisms yet exist to account for these benefits in the market place. (3) There is currently a clea~r societal emphasis on short-term profits. Because m a n y
Table l Projections of USA renewable energy pet¢~fial in 2020 (all 2"igures in exaioules) Renewable technology
Union of C,,ncerned Scientists
hydro solar wind biomass geothermal
3.5 20 5 !5 0.25
total renewables total energy
43.5 84
Business as ususal [5]
Enhanc~ d R, D & D 5]
Market premi,,~.~ [5]
3.3 2,1 (1.2, i ,8 7.4 9,9
4.5 4.4 (3. ~) 4.0 1? 3 2.6
~,q 4.4 (3.5) 2,8 0.5 1.7
15.5 124
27.8 ! 24
0165-1633/91/$03.50 ',- 199l - Llsevier ~cience ~..t, u o,,~.,~,~,, h ~ e ~ , -.r~~,.~,.,~i rights i~,s~,rved
23,3 124
P. DeLaquil / Prospectsfor solar thermal electricity generation
79
renewable energy tech~~ologies have high capital costs (with very low annual costs) they are v.ot as financially attractive in the short term as low capital cost technologies (even those with high, or highly uncertain, annual eosts). t ~ Declining federal R & D support (in tt~ USA) for ~--,'..... r,~°- has delayed mm~v possiHe, improvements in the technologies and the past adw_inistration's unwillingness to support demonstration projects has postponed the commercial introduction of promisi~ig technologies_ (5) Governments confiaue to provl.de vet3" large s,~bsidies to conventional energy sources. A recent repot' showed that ia ~,oe USA almost $41 billion of a total of $44 billion i_~.energy ~apports went to established, conventional technologies of coal, oil, gas and nuclear [3]. Incredibly, this amount does not include the costs 0t" defending USA oil interests in the Persian Gulf.
2. P o l e n t i a | . . . . t.l.~,,,,~..,, o t ~¢nt.wahio p o w e r s o t t r e e ~
A. recent report by the Un.on of Co~cerned Scientists (UC:?,) [4] contained a scenario for reducing ann0 A t-P2 emissions from the USA by about 50 percent by ~,,:c. The key assumptions to this scenario are that strong .o,overnmental the year -,--,c, leadership, combined with increased R & D funding and appropriate market inee~,:tive.~ can maintain USA primary energy consumption at the 1989 level ihro,.%il improvements in energy efficiency and incrtJsed utilization of-enew_.able power sources such that they provide about 50 percent of our p r i m a ~ e n e r g y needs by 2020. A,e the projections of the t.JCS report wild-eyed fantasies? Table 1 show.~ projections by !he five Ud;. national laboratories that have respor.sibi~ity ior renewable energy *e,-hnologv. __ . ~levelopment next to the UCS projections. The l~.boratory projectioreJ were generated for three spc:c:,fic scenarios i5]. Business as usual a;~umes ,hat the ren,e,,able enexgy technologies must compete in the current market c,,mat~ ': - against conventional fuei sources. Fossil fuel price escalation', is modest, and federal R & D fur, ding remains ~.t current levels. Given only one-third of the UCS projection. these conditions r.e. .n. e. .w a' .o. .~. ~.azz ~oh;.eve . ...... The e n h a n c e d R & D st:~i~:~rio assumes the same market conditions but with significznt ir~cx:ease:~in federal fund; for research, dc e|opment and demonstration of renewable energy technolof:~es which accelerate,: their market introduction ar.d market competi~i,,~:o.:~s. In th!~ scenario, ceaewabies achieve almost two-thirds of :he UCS projc,:tlon. In the ,~arket p r e m i u m s scenario, there was no increase m Y~aeral R & D funding, bai _local environmental con~',erns were assumed to b:ve generated a 2 e / k W h premium for electricity produced I',, rer~e~ able 9owe~ :,purees. a $2,/MB~u premium for renewable energy technologies which reduced the use of oil, and $ ! / M B t u premium for biofueis. This scenario shows renewable,, achieving over 50 percent of the UCS projections.. My conclu,iot~ from this comparison i~ that giveu the comblaed policies recommended by the UCS, their projections for the t,t-lizatlon of renewable power sources
~0
P. DeLaquil / Prospectsfor solar thermal electricity generation
are achievable. Furthermore, this level of utilization would result in the elimination of between 800 and 900 million tons of CO 2 emissions in the year 2020, and would represent a major step toward the 50 to 80 percent reductions in CO 2 emissions that are considered necessary to stabilize the global climate [6]. In table 1, the figures given in parenthesis under solar primary energy contribution in 2020 indicate the contribution of solar thermal-electric systems. At a typical solar thermal power plant capacity factor of 35%, 1 EJ represents a generating capacity of 30000 MW!
3. Solar thermaJ technology development How will this large utilization of solar thermal power plants be achieved? Currently, solar thermal parabolic trough technology, as developed by Luz International, Ltd., is the only solar thermal-electric technology in the market place. Solar central receiver power plants are ready for a utility-scale demonstration. Parabolic dish-Stifling power systems are entering the technology development stage, with the first prototype system modules being tested. Cooperation between government and industD" will be necessary to complete the commercialization of these promising technologies. Government support for technology development and demonstration projects is n~cessa~ but it is not sufficient. Market incentives are needed to over'come barriers in the user and financial communities which exist because these technologies are new and unfamiliar, may contain unknown risks, and represent a threat to existing technologies and interests. Luz International is the solar thermal electric success story. Since the early 1980's, they have been building, operating and developing solar thermal power plants in the Mojave Desert of California. They currently %ave eight operating plants with a total capacity of 274 MW. Their ninth plant (80 MW) is currently under construction, and they have contracts for another 300 MW. Luz has been successful for a variety of reasons. First, is th~ external conditions and market incentives which existed in the early 1980's when they were introducing their technology into the market place. Federal investment tax credits, and federal and state solar energy tax credits provided a 40% deduction of the capital cost of their early plants. Five-year accelerated depreciation further help their project financing, and both PURPA and high fuel prices gave rise to very attractive power purchase contracts which Luz continues to build on today. Second, Luz possesses a long-term vision and commitment to develop solar energy. Their incentive is not short-term profits. Third, they have been willing to accept risk and shelter their investors from technical uncertainties. Lastly, they have a great deal of financial acuity and have shown that tiffs element of business is just as (maybe more) important than technical acuity.
References [1] O. Hohmeyer,"Social Costs of Energy Consumption", Springer, Berlin 0988). [2] L. Brown et al., "State of the World 1988", A Worldwatch Institute Rer~ort on Progress Toward a Sustainable Society,W.W. Norton and Co., New York (1988).
P. DeLaquil / P~osFectsfor solar thermal electricity generaeton
81
[3] H.R. Heede et al., ~'The Hidden Cost of Energy", Center for Renewable Resources, Washington, DC (1985). [4] M. Brower, "Coo~ Energy: The Renewable Solution to Global Warming", Union of Concerned Scientists, Cambridge, MA (1990). [5] "The Potential of Renewable Energy: An lnterlaboratory Whi~e Paper", Idaho National Engineering Laboratory, Los Alamos National Laboratory, Oak Ridge National Laboratory, Sandia National Laboratories, Solar Energy Research Institute, SERI/TP-260-3674 (March !~990). [6] "'Poli':y Options for Stabilizing Global Climate", Environmental Protection Agency Report to t.ongress (draft, February 1989).
Note by the editor While the foregoing clearly shows the large potential for solar thermal energy in the USA, one mi[;~-ht ask what the European prospects and interests in this technology are. It is certainly not the potential for an extended near-term application in their own countries, since climatic conditions for this technology in Europe are not very favourab~e. One reason is the awareness of Europeans that producing electricity by combustion processes is environmentally dangerous and should be limited as much as reasonably possible. And this on a global scale. Another reason is their awareness of the fact that solar radiation could satisfy, in a relatively clean way, all energy needs as long as the world as we know it exists, provided suitable power plants are developed and applied on a large scale. The solar ex erts k~ow frere experiments and plant studies thet thermal solar applications can, with relatively modest development costs, become competitive with established energy sources, particularly for developing countries in the sun belts of Africa and Asia. And because European companies traditionally export a high proportion of the goods they produce, this then is the incentive for their interest. It has becoi~e clear, however, that this incentive is not sufficient for companies to spend their own money for the necessary developments. (Also in the development of nuclear energy this has been and still is the case.) Although the finances needed for the development of solar mergy are small compared to some of the me:re do,,.~btful activities of mankind, the developing countries, that would be first to profit fromits application, cannot pay for its development. It follows from this, that in the overriding interests of environment, fossil energy conservation and the relations between first, second and third world countries, public funding by the rich countries is needed in the first instance. Once this has been do~e, prospects for the Europeans are good. Their tradition in adapting for the needs of a wide range of customers will help them to provide suitable solutions for the first markets in developing countries.
Sol:tr Energy Materials 24 (1091) 78-81 Nolh-Holland
Prospects for solar thermal electricity generation an introduction Pascal D e L a q u i ! Renewable ~nerg?; Manager, Bechtel Group Inc., 50 Beale Street, San Francisco. CA 94105, US,4
1. httroduetion The future potential for solar thermal electric power plants is quite significant. The size of the renewable energy resource ba~,e for the U n i t e d States of A m e r i c a alone is almost 500 time~ its current p r i ~ a r y energ'~" consumption._ _. Unfortunately, the levels of curren~ utilization are ,.~uite small. Why have these technologies not m a d e a la~'g,:r c~.::a,nbution to today's market" The answer is that significant barriers still exist. Tb,. most importz:U of the~e a,_'e: (1) The current econo:ruc cll.,,,:~, of low fuel prices. As the recent events in the Middle Fast show .~nce , ~ , m , this m a y change veu, rap!dly. (2) The ct, rrent er~ergy market, as well as ~.he financial community, is insensitive to the social ~iid enviror.mental benefits of renewable energy s~ources. The converse of this is that the social and e n v i r o n m e n t a l , . ~t., of ,~,~,, , ~ , , u~c ai.~ . u t o~.,,~ accounted for in ~he market place. Estimates of the ~OCl.~ - " ' 'and environmental costs of electricity production from fossil fuels range from 2 to 6 ¢,/kWh. [1.2]. Unfortunately, no mechanisms yet exist to account for these benefits in the market place. (3) There is currently a clea~r societal emphasis on short-term profits. Because m a n y
Table l Projections of USA renewable energy pet¢~fial in 2020 (all 2"igures in exaioules) Renewable technology
Union of C,,ncerned Scientists
hydro solar wind biomass geothermal
3.5 20 5 !5 0.25
total renewables total energy
43.5 84
Business as ususal [5]
Enhanc~ d R, D & D 5]
Market premi,,~.~ [5]
3.3 2,1 (1.2, i ,8 7.4 9,9
4.5 4.4 (3. ~) 4.0 1? 3 2.6
~,q 4.4 (3.5) 2,8 0.5 1.7
15.5 124
27.8 ! 24
0165-1633/91/$03.50 ',- 199l - Llsevier ~cience ~..t, u o,,~.,~,~,, h ~ e ~ , -.r~~,.~,.,~i rights i~,s~,rved
23,3 124
P. DeLaquil / Prospectsfor solar thermal electricity generation
79
renewable energy tech~~ologies have high capital costs (with very low annual costs) they are v.ot as financially attractive in the short term as low capital cost technologies (even those with high, or highly uncertain, annual eosts). t ~ Declining federal R & D support (in tt~ USA) for ~--,'..... r,~°- has delayed mm~v possiHe, improvements in the technologies and the past adw_inistration's unwillingness to support demonstration projects has postponed the commercial introduction of promisi~ig technologies_ (5) Governments confiaue to provl.de vet3" large s,~bsidies to conventional energy sources. A recent repot' showed that ia ~,oe USA almost $41 billion of a total of $44 billion i_~.energy ~apports went to established, conventional technologies of coal, oil, gas and nuclear [3]. Incredibly, this amount does not include the costs 0t" defending USA oil interests in the Persian Gulf.
2. P o l e n t i a | . . . . t.l.~,,,,~..,, o t ~¢nt.wahio p o w e r s o t t r e e ~
A. recent report by the Un.on of Co~cerned Scientists (UC:?,) [4] contained a scenario for reducing ann0 A t-P2 emissions from the USA by about 50 percent by ~,,:c. The key assumptions to this scenario are that strong .o,overnmental the year -,--,c, leadership, combined with increased R & D funding and appropriate market inee~,:tive.~ can maintain USA primary energy consumption at the 1989 level ihro,.%il improvements in energy efficiency and incrtJsed utilization of-enew_.able power sources such that they provide about 50 percent of our p r i m a ~ e n e r g y needs by 2020. A,e the projections of the t.JCS report wild-eyed fantasies? Table 1 show.~ projections by !he five Ud;. national laboratories that have respor.sibi~ity ior renewable energy *e,-hnologv. __ . ~levelopment next to the UCS projections. The l~.boratory projectioreJ were generated for three spc:c:,fic scenarios i5]. Business as usual a;~umes ,hat the ren,e,,able enexgy technologies must compete in the current market c,,mat~ ': - against conventional fuei sources. Fossil fuel price escalation', is modest, and federal R & D fur, ding remains ~.t current levels. Given only one-third of the UCS projection. these conditions r.e. .n. e. .w a' .o. .~. ~.azz ~oh;.eve . ...... The e n h a n c e d R & D st:~i~:~rio assumes the same market conditions but with significznt ir~cx:ease:~in federal fund; for research, dc e|opment and demonstration of renewable energy technolof:~es which accelerate,: their market introduction ar.d market competi~i,,~:o.:~s. In th!~ scenario, ceaewabies achieve almost two-thirds of :he UCS projc,:tlon. In the ,~arket p r e m i u m s scenario, there was no increase m Y~aeral R & D funding, bai _local environmental con~',erns were assumed to b:ve generated a 2 e / k W h premium for electricity produced I',, rer~e~ able 9owe~ :,purees. a $2,/MB~u premium for renewable energy technologies which reduced the use of oil, and $ ! / M B t u premium for biofueis. This scenario shows renewable,, achieving over 50 percent of the UCS projections.. My conclu,iot~ from this comparison i~ that giveu the comblaed policies recommended by the UCS, their projections for the t,t-lizatlon of renewable power sources
~0
P. DeLaquil / Prospectsfor solar thermal electricity generation
are achievable. Furthermore, this level of utilization would result in the elimination of between 800 and 900 million tons of CO 2 emissions in the year 2020, and would represent a major step toward the 50 to 80 percent reductions in CO 2 emissions that are considered necessary to stabilize the global climate [6]. In table 1, the figures given in parenthesis under solar primary energy contribution in 2020 indicate the contribution of solar thermal-electric systems. At a typical solar thermal power plant capacity factor of 35%, 1 EJ represents a generating capacity of 30000 MW!
3. Solar thermaJ technology development How will this large utilization of solar thermal power plants be achieved? Currently, solar thermal parabolic trough technology, as developed by Luz International, Ltd., is the only solar thermal-electric technology in the market place. Solar central receiver power plants are ready for a utility-scale demonstration. Parabolic dish-Stifling power systems are entering the technology development stage, with the first prototype system modules being tested. Cooperation between government and industD" will be necessary to complete the commercialization of these promising technologies. Government support for technology development and demonstration projects is n~cessa~ but it is not sufficient. Market incentives are needed to over'come barriers in the user and financial communities which exist because these technologies are new and unfamiliar, may contain unknown risks, and represent a threat to existing technologies and interests. Luz International is the solar thermal electric success story. Since the early 1980's, they have been building, operating and developing solar thermal power plants in the Mojave Desert of California. They currently %ave eight operating plants with a total capacity of 274 MW. Their ninth plant (80 MW) is currently under construction, and they have contracts for another 300 MW. Luz has been successful for a variety of reasons. First, is th~ external conditions and market incentives which existed in the early 1980's when they were introducing their technology into the market place. Federal investment tax credits, and federal and state solar energy tax credits provided a 40% deduction of the capital cost of their early plants. Five-year accelerated depreciation further help their project financing, and both PURPA and high fuel prices gave rise to very attractive power purchase contracts which Luz continues to build on today. Second, Luz possesses a long-term vision and commitment to develop solar energy. Their incentive is not short-term profits. Third, they have been willing to accept risk and shelter their investors from technical uncertainties. Lastly, they have a great deal of financial acuity and have shown that tiffs element of business is just as (maybe more) important than technical acuity.
References [1] O. Hohmeyer,"Social Costs of Energy Consumption", Springer, Berlin 0988). [2] L. Brown et al., "State of the World 1988", A Worldwatch Institute Rer~ort on Progress Toward a Sustainable Society,W.W. Norton and Co., New York (1988).
P. DeLaquil / P~osFectsfor solar thermal electricity generaeton
81
[3] H.R. Heede et al., ~'The Hidden Cost of Energy", Center for Renewable Resources, Washington, DC (1985). [4] M. Brower, "Coo~ Energy: The Renewable Solution to Global Warming", Union of Concerned Scientists, Cambridge, MA (1990). [5] "The Potential of Renewable Energy: An lnterlaboratory Whi~e Paper", Idaho National Engineering Laboratory, Los Alamos National Laboratory, Oak Ridge National Laboratory, Sandia National Laboratories, Solar Energy Research Institute, SERI/TP-260-3674 (March !~990). [6] "'Poli':y Options for Stabilizing Global Climate", Environmental Protection Agency Report to t.ongress (draft, February 1989).
Note by the editor While the foregoing clearly shows the large potential for solar thermal energy in the USA, one mi[;~-ht ask what the European prospects and interests in this technology are. It is certainly not the potential for an extended near-term application in their own countries, since climatic conditions for this technology in Europe are not very favourab~e. One reason is the awareness of Europeans that producing electricity by combustion processes is environmentally dangerous and should be limited as much as reasonably possible. And this on a global scale. Another reason is their awareness of the fact that solar radiation could satisfy, in a relatively clean way, all energy needs as long as the world as we know it exists, provided suitable power plants are developed and applied on a large scale. The solar ex erts k~ow frere experiments and plant studies thet thermal solar applications can, with relatively modest development costs, become competitive with established energy sources, particularly for developing countries in the sun belts of Africa and Asia. And because European companies traditionally export a high proportion of the goods they produce, this then is the incentive for their interest. It has becoi~e clear, however, that this incentive is not sufficient for companies to spend their own money for the necessary developments. (Also in the development of nuclear energy this has been and still is the case.) Although the finances needed for the development of solar mergy are small compared to some of the me:re do,,.~btful activities of mankind, the developing countries, that would be first to profit fromits application, cannot pay for its development. It follows from this, that in the overriding interests of environment, fossil energy conservation and the relations between first, second and third world countries, public funding by the rich countries is needed in the first instance. Once this has been do~e, prospects for the Europeans are good. Their tradition in adapting for the needs of a wide range of customers will help them to provide suitable solutions for the first markets in developing countries.