Bold ideas - the big solar plan

By 2050, solar energy could end America's dependence on imported fuel and reduce greenhouse gas emissions into the air

By Ken Zwiebel, James Mason and Vassilis Patanakis

Fuel prices for transportation and heating are high today, and they will remain high in the future. The United States is immersed in a war in the Middle East, partly to protect its interests in the field of oil imports. And with the demand for fossil fuel in China, India and other countries rising rapidly, the danger of future wars over energy sources is greater than ever. Meanwhile, cars and power plants all over the world burn coal, oil and natural gas and continue to pour into the atmosphere millions of tons of pollutants and greenhouse gases that threaten the planet.

Well-intentioned scientists, engineers, economists and politicians have proposed a variety of measures to slightly reduce the use of fossil fuels and the emissions of the gases. But these steps are not enough. The United States must take bold action to wean itself off fossil fuels. The analysis we did convinced us that the logical solution is a wholesale transition to solar energy.

There is no rival to the potential inherent in solar energy. The amount of energy coming from the sun to the earth for 40 minutes is equal to the annual consumption of the entire world. The United States was lucky and received a great natural resource: at least 650,000 square kilometers of land in the southwest of the country are suitable for building solar power plants. The sun illuminates this area with radiation equal to 4,500 quadrillion (4,500×1015) British thermal units (BTU) each year. If only 2.5% of this radiation were converted into electricity, it would be enough to supply all the energy consumed by the United States in 2006.

For the entire United States to consume solar electricity, vast tracts of land must be covered with photovoltaic panels and concave heating mirrors. On top of that, direct current (DC) transmission infrastructure must be established to efficiently transmit electricity throughout the country.

The technology is ready. In the following pages, we will present a master plan for supplying 69% of the electricity of the United States and 35% of its general energy (including the energy needed for transportation) through solar energy until 2050. We predict that this energy will be sold to consumers at prices equivalent to electricity prices in the United States today, about five cents per kilowatt - an hour (kWh). If additional energy sources, such as wind, biomass and solar energy are developed, these renewable energy sources could provide all of the United States' electricity and 90% of its total energy by 2100.

The federal government will need to invest more than $400 billion over the next 40 years to complete the plan by 2050. That's a substantial investment, but the payoff is even greater. Solar power plants use very little, if any, fuel and save billions of dollars over many years. The new infrastructure will replace 300 coal stations, 300 natural gas stations and all the fuels they consume. The plan would eliminate virtually all fuel imports to the United States, cut its trade deficit by a fundamental cut, and relieve political tension in the Middle East and elsewhere. The solar technologies are almost non-polluting, so the program will also reduce the greenhouse gases emitted from power plants by 1.7 billion tons per year. Also, the emission of another 1.9 billion tons of greenhouse gases per year will be saved due to the transition from cars with gasoline engines to plug-in hybrid cars, the electricity to charge them will come from the solar power grid. In 2050, the United States will emit only 62% of the amount of carbon dioxide it emitted in 2005, and thus global warming will be significantly reduced.

Photovoltaic farms

In recent years, the price of the photovoltaic cells and the solar units has dropped significantly and this paves the way for deployment on a wide scale. There are many types of cells, but the cheapest units today are made of thin layers of cadmium telluride. To reach an electricity supply at a price of 6 cents per kilowatt-hour by 2020, the cadmium telluride units will have to convert energy with an efficiency of 14%, and the price of the systems will have to drop to $1.20 per watt. Today the efficiency is 10% and the price of the unit is 4 dollars per watt. There is no doubt that more progress is needed, but technology is developing rapidly. Only in the last year did the efficiency of the commercial facilities rise from 9% to 10%. It is important to mention that as the units improve, the photovoltaic cells installed on the roofs of the houses become more profitable for the homeowners and lower the demand for electricity during the day.

According to our plan, the photovoltaic technology will provide almost 3,000 gigawatts (GW) of electricity, which will be produced in photovoltaic arrays that will be deployed by then in an area of ​​approximately 80,000 square kilometers. Even though this area sounds enormous in size, from the facilities that are already operating today, it can be proven that the area needed for such a power of solar electricity in the southwest of the United States is smaller than the area of ​​a coal station, if the areas of the mines are also taken into account. Studies done by the American National Renewable Energy Laboratory in Golden, Colorado show that there is more than enough free land in the southwestern United States and it will not be necessary to use environmentally sensitive areas, population centers or areas with difficult terrain. Jack Lovell, a spokesman for the Arizona Department of Water Conservation, said that more than 80 percent of the state's land is not privately owned, and that Arizona is very interested in developing its solar potential. The mild nature of the photovoltaic installations (including not consuming water) minimizes environmental concerns.

The most important technological advance yet to be achieved is increasing the efficiency of the photovoltaic units to 14%. Although the efficiency of commercial units will never match the efficiency of laboratory solar cells, at the US National Renewable Energy Laboratory cadmium telluride cells have already reached 16.5% efficiency, and they are getting better. At least one manufacturer, First Solar of Perrysburg, Ohio, managed to increase the efficiency of its units from 6% in 2005 to 10% in 2007, and it aims to reach 11.5% efficiency by 2010.

Pressure caves

The main limitation of solar energy is the small amount of electricity that can be produced from it when the sky is cloudy and the lack of the ability to produce electricity at night. Therefore, during sunny hours they will have to generate excess electricity, store it and use it during dark hours. Most energy storage devices, such as batteries for example, are expensive and inefficient.

The energy stored in compressed air is a successful alternative. The electricity produced in the photovoltaic stations will be used to compress air and inject it into underground caves, abandoned mines, aquifers and empty natural gas wells. When necessary, they will release the compressed air and use it to drive turbines to produce electricity. This requires additional energy obtained from burning a small amount of natural gas. Compressed air energy storage facilities have been operating efficiently in Hannover, Germany since 1978 and McIntosh, Alabama since 1991. The turbines burn only 40% of the natural gas that would have been required if they had only operated with it, and improved heat preservation technologies could reduce the amount to 30%.

Research done by the Electric Energy Research Institute in Palo Alto, California shows that the current price of energy stored using compressed air is about half the price of energy stored in lead-acid batteries. The study also found that these facilities will increase the price of a kWh produced using photovoltaic cells by three or four cents, so its price in 2020 will be eight or nine cents.

The electricity that will be produced in the solar farms in the southwest of the United States will be sent on high voltage lines in direct current to the air compression facilities throughout the country, where electricity will be produced through turbines throughout the year. The key to the success of the program is finding suitable sites for it. A mapping study by the natural gas industry and the Electric Power Research Institute shows that suitable geological formations are spread over 75% of the United States, many of them near metropolitan areas. The compressed air energy storage facilities will look very similar to the natural gas storage systems of the United States. This industry today stores 230 billion cubic meters of gas in 400 underground reservoirs. By 2050, our plan will require 15 billion cubic meters of compressed air at a pressure of 75 atmospheres. Although the development will be challenging, there is plenty of storage space available, and it is likely that the natural gas industry will find it appropriate to invest in such a storage network.

hot salt

Another technology that may possibly provide a fifth of the solar energy in our vision is known as concentrated solar energy. According to this method, long metal mirrors focus the sunlight in a liquid-filled tube and heat it as if they were a giant magnifying glass. The hot liquid is passed through a heat exchanger that produces steam that turns a turbine.

To preserve the energy, the pipes pass through an insulated tank filled with molten salt, which effectively preserves the heat. This heat is extracted during the night to create steam. But despite its effectiveness, the molten salt cools slowly, so the saved energy must be used within one day.

Nine plants of concentrated solar energy with an output of 354 megawatts have been reliably producing electricity for years in the United States. A new power plant with an output of 64 megawatts was commissioned in Nevada in March 2007. But these plants do not have a heat storage facility. The first commercial power plant to include such a facility is currently being built in Spain. Its output will be 50 megawatts, and it will be able to store the heat for seven hours using molten salt. More such stations are planned around the world. Our plan would require heat storage for 16 hours to provide electricity for 24 hours a day.

The existing facilities prove that generating electricity through the concentration of solar energy is a viable option if the costs come down. Increasing facilities and continuing research will help with this. A report by the "Solar Task Force" of the Association of Governors of the Western States of the United States stated in 2006 that by 2015, power plants will be able to produce electricity by concentrating solar energy at a price of ten cents per kWh or less, provided that stations are built with an output of 4 G each Gigawatt. Production efficiency will also improve if ways are found to raise the temperature of the fluids used to convert the heat. Engineers are investigating how it will be possible to use the molten salt itself as a heat conversion fluid, and in this way reduce the heat losses and the invested capital. However, salt is a corrosive substance (causes corrosion), and to use it, a more durable pipe system is necessary.

Producing electricity through the concentration of solar radiation and producing it through photovoltaic cells are two different technological ways. Neither of them is sufficiently developed, therefore our plan advocates the full deployment of both methods by 2020 to allow them to reach maturity. In addition, different combinations of solar technologies may evolve to meet economic requirements. As facilities grow, engineers and accountants will be able to reassess the pros and cons of each method, and investors will be able to choose which technology to invest more in.

Direct current is also a problem

The geographic distribution of solar energy is of course different from the electricity supply pattern in the United States. The power plants operating today using coal, oil, natural gas and nuclear energy dot the landscape, and are relatively close to the places where electricity is needed. In contrast, most of the solar electricity production will be carried out in the southwest of the United States. The current alternating current (AC) transmission line system is not robust enough to transmit electricity to consumers over such distances due to too much energy loss.

Studies done at the American Oak Ridge National Laboratory show that direct current high voltage lines lose much less energy than alternating current lines of the same length. Therefore, it will be necessary to establish a new transmission infrastructure of high voltage direct current (HVDC) lines. The infrastructure will be spread everywhere from the southwest of the United States to its borders. The lines will end in alternating current conversion stations, and it will reach consumers via the old regional transmission lines.

Already today the system capacity of the alternating current does not meet the requirements. Power shortages are felt in California and other areas. Direct current lines are cheaper to set up and require less space than similar alternating current lines. In the United States today, 800 km of direct current high voltage lines are deployed, and they have proven their reliability and efficiency. Therefore, there does not seem to be a need for significant technological progress in this area, although richer operating experience could improve the service. The "Southwest Texas Power Reserve" plans to build a combined transmission system of direct current and alternating current to enable the establishment of a power plant that will generate electricity from the wind with a capacity of ten gigawatts in West Texas. Trans-Canada plans to deploy 3,500 km of direct current high-voltage lines, which will transmit electricity from windmills in Montana and Wyoming south to Las Vegas and even further.

Phase I: From now until 2020

We have put a lot of thought into how to operate our large solar program. We foresee two distinct phases. The first, between now and 2020, must bring the price of solar energy to a competitive level in mass production. This step will require the American government to commit to a 30-year loan, agree to purchase electricity and subsidize it. The annual aid package will gradually increase from 2011 to 2020. Until then, the solar technologies will stand on their own. The cumulative subsidy will reach a total of 420 billion dollars (later we will explain how to pay this bill).

By 2020, power plants will be built that will generate 84 gigawatts of electricity using photovoltaic cells and concentrating solar radiation. At the same time, the direct current transmission infrastructure will be deployed. The system will be established along land corridors on the sides of the interstate highways where right of use already exists today, while minimizing the need to purchase land and deal with other legal hurdles. The infrastructure will reach the big markets of the big cities in the west of the United States and in the east.

Building an output capacity of 1.5 gigawatts of electricity using photovoltaic cells and another 1.5 gigawatts of electricity by concentrating solar radiation each year from the first five years could stimulate many manufacturers to increase the facilities they build. In the next five years, the construction rate will increase to 5 gigawatts per year in each technology, and thus the companies will be able to optimize their production lines. Therefore, the price of solar electricity will decrease and will approach six cents per kWh. This schedule for the implementation of the plan is a practical schedule. Nuclear power plants producing more than 5 gigawatts per year were built in the United States every year from 1972 to 1987. Furthermore, solar systems can be built faster than conventional power plants because they are simple to design and have fewer environmental and safety complications.

Phase B: 2020 to 2050

It is extremely important that large economic incentives continue to accompany the process until 2020 to prepare the ground for sustainable growth thereafter. The extension of our model until 2050 was therefore done with a conservative approach. We did not include technological improvements or cost reductions after 2020. We also assumed that energy demand in the United States would continue to increase at a rate of 2050 percent per year. According to this scenario, in 69 the solar power plants will provide 344% of the electricity consumed by the 3 million plug-in hybrid vehicles, which will by then replace their fuel-powered counterparts. This will be a key tool for reducing dependence on fuel imports and reducing greenhouse gas emissions. This industry will create about XNUMX million jobs, mainly in the production of solar components, a number many times greater than the number of jobs that will be lost in the United States due to the reduction of the fuel industry.

The significant reduction in oil imports will reduce trade balance payments by $300 billion per year, assuming the price of a barrel of crude oil is $60 (the average price in 2007 was higher than this price). After the construction of the solar facilities, it will be necessary to maintain and repair them, but the sunlight will remain free forever, so the fuel savings will double every year. The investment in solar energy will increase the national security of the United States in the field of energy, reduce the financial burden of the military, and greatly reduce the social cost of pollution and global warming, from health problems to the destruction of beaches and agricultural lands.

Surprisingly, the large solar plan will reduce energy consumption. Even assuming a 100 percent annual increase in electricity demand, annual consumption will decrease from 2006 quadrillion BTUs in 93 to 2050 quadrillion BTUs in XNUMX. The reason for this is that a lot of energy is consumed today for the production and processing of mineral fuels and additional energy is lost in burning them and regulating gas emissions.

In order to meet this forecast by 2050, 120,000 square kilometers of land will be needed to establish the solar power facilities. This is a large area, but it is only 19% of the suitable land in the southwestern United States. Most of this area is pit land, has no competing use value, and will not be contaminated. We assumed that only 10% of the solar output would come from distributed photovoltaic installations that would be placed, for example, on the roofs of houses or industrial buildings throughout the country. But as prices fall, the share of this field will be larger.

After 2050

Although it is impossible to predict exactly what will happen in more than 50 years, we have extended our scenario to 2100 to demonstrate the potential of solar energy. By then, based on our plan, the annual demand for energy (including the demand for energy in the field of transportation) will be 140 quadrillion BTU, and the output of electricity production will be seven times greater than today's production.

Again we took a conservative approach: we estimated what would be the required output from solar power plants under the worst radiation conditions, as measured in the southwestern United States in the winter of 1983-1982 and in 1992 and 1993 after the eruption of the Pinatubo volcano. We took the data from the American solar radiation database from 1961 to 2005. Here again we did not take into account technological improvements or a price drop after 2020, although it is likely that 80 years of continuous research will lead to optimization, improvement of solar energy storage methods and a price drop .

According to these assumptions, the energy requirements of the United States will be met as follows: 2.9 terawatts of photovoltaic energy from the electric system, 7.5 terawatts to be stored using compressed air, 2.3 terawatts of power plants to concentrate sunlight and 1.3 terawatts from distributed photovoltaic systems. The electricity supply will also include 0.2 terawatt of electricity from windmills, 0.25 terawatts from geothermal power plants and 0.5 terawatts from biomass fuel production. The model also includes 430,000 terawatts of thermal energy that will be used for direct heating and cooling of buildings. The solar systems will cover an area of ​​XNUMX square kilometers, which is smaller than the corresponding area in the southwestern United States.

This array of renewable energy could produce all of the United States' electricity in 2100 and more than 90% of its total energy. In the spring and summer, the solar infrastructure will produce enough hydrogen to power more than 90% of the vehicles and to replace the small power plants that will burn natural gas to help compress the air for the turbines. Another 180 billion liters of biofuel will complete transportation requirements. The carbon dioxide emissions associated with energy production will be 92% lower than the carbon dioxide emissions associated with energy production in 2005.

Who will pay?

Our model is not an austerity program. He takes into account an increase of one percent per year in the demand for energy, which will make it possible to maintain today's standard of living, alongside an expected streamlining of energy production and use. Perhaps the biggest question is where do you get $420 billion for a general overhaul of the energy infrastructure in the United States. One of the most popular ideas is a carbon tax. The International Energy Agency proposes a tax of 40 to 90 dollars per ton of coal to encourage electricity producers to adopt systems for capturing and storing carbon dioxide and thus reduce its emissions. The meaning of this tax is to raise the price of electricity by one or two cents per kWh. Our plan is cheaper. The 420 billion dollars can be raised through a carbon tax of half a cent per kWh. Today the price per kilowatt hour is six to ten cents (the price in Israel is equal to 12 cents - the editors), so an increase of half a cent is a reasonable increase.

The US Congress can create economic incentives if it adopts a national renewable energy plan. It is worth comparing this to the agricultural subsidy policy used in the United States for reasons of national security. A program to support solar energy will secure the nation's energy future, and is essential to the country's long-term health. The loans will be gradually deployed from 2011 to 2020. The support will end between 2041 and 2050, after an acceptable repayment period of 30 years. There will be no need to subsidize the transmission companies because they will be able to finance the construction of the direct current high voltage lines and the construction of the conversion stations in exactly the same way that they finance the layout of alternating current power lines today: charging a fee for the transmission of electricity.

Although $420 billion is a substantial amount, the annual expenditure would be less than the cost of the agricultural subsidy policy in place today. It will also be lower than the tax imposed to finance the construction of the high-speed communication infrastructure of the United States in the last 35 years. In addition, this investment will free the United States from the political and budgetary burden it is forced to bear due to international energy struggles.

Without a government subsidy the big solar plan is not possible. Other countries have also reached similar conclusions: Japan is already building a large and subsidized solar infrastructure and Germany has also inaugurated a similar national program. The expense is indeed large, but, as mentioned, it must be remembered that the source of energy, sunlight, does not cost anything. Apart from that, there are no annual expenses for fuel or for pollution control as there are when using coal, oil or nuclear power. There is only a small expenditure on natural gas in air compressor stations, and hydrogen or bio-fuel could replace it in the future. If you take into account the fuel savings, the price of solar energy in the coming decades will be a real bargain. But we can't afford to wait until then to start the upgrade process.

Critics have raised other concerns. For example, that a lack of raw materials could prevent the construction of large facilities. Although such a temporary shortage is possible in a quick setup, there are several types of cells today that use different combinations of materials. Better processing and recycling methods also reduce the amount of raw materials needed. Furthermore, in the long run it will be possible to recycle old solar cells to produce new cells. This will change the picture of energy supply: from a state of dependence on fuel to a state where recycled materials will be used.

However, the biggest obstacle to implementing a renewable energy system in the United States is not technological or financial. The obstacle is actually the public's lack of awareness that solar energy is a practical alternative that can also drive transportation. Far-sighted thinkers must try to expose the citizens of the United States and its leaders and scientists to the potential inherent in solar energy. We believe that when Americans recognize this, the desire for energy independence and the need to reduce carbon dioxide emissions will motivate them to adopt a national solar program.

Key Concepts A large-scale transition from power plants operating with coal, oil or natural gas and nuclear reactors to solar power plants could provide 69% of the United States' electricity and 35% of its total energy by 2050.

It will be necessary to allocate a large area in the southwest of the United States in order to establish photovoltaic arrays. The excess energy produced during the day will be stored underground using air compression and will be used at night. Large power plants will also be built that will operate by concentrating solar energy. A new transmission infrastructure that will operate in direct current will flow the solar electricity throughout the country. However, government aid in the amount of 420 billion dollars will be needed from 2011 to 2050 to finance the construction of the infrastructure and to bring the price of electricity to a competitive level.

Photovoltaic cells

In 2050, photovoltaic farms will cover about 80,000 square kilometers of peatland in the southwestern United States. They will resemble the Tucson Electric Company farm in Springerville, Arizona, which was established in 2000. In such farms, many photovoltaic cells are connected to each other to form a single subunit, and the subunits are wired together to form an array. The direct current from each array flows to the transformer, and it transfers it to the high voltage lines leading to the national grid. In an electric cell that operates through a thin layer, the energy of the photons coming from the sun releases electrons from a layer of cadmium-tellurium. The electrons cross a junction, flow to the top conduction layer and flow to the back conduction layer, thus creating the electric current.

Abundant resources
Solar radiation is widespread in the United States, especially in its southwestern regions. There are several options for distributing the 120,000 square kilometers of solar collectors (white circles) needed for the grand solar plan. One of them is shown here to scale.

About the authors

By Ken Zwiebel, James Mason and Vasilis Patenakis

Ken Zweibel (Zweibel), James Mason (Mason) and Vasilis Fthenakis (Fthenakis) met ten years ago in joint research on the life cycle of photovoltaic cells. Zvibel is the president of Primestar Solar from Golden, Colorado. For 15 years he directed the Thin Film Photovoltaic Cell Research Partnership at the US National Renewable Energy Laboratory. Mason directs the fight for solar energy and the Hydrogen Research Institute in Farmingdale, New York. Patenakis heads the Photovoltaic Cell Environmental Research Center at the American National Laboratory in Brookhaven and serves as a professor and director of the Institute for Life Cycle Analysis at Columbia University.

underground storage

The excess energy that will be produced during the day in the photovoltaic farms will be able to be sent via power lines to sites close to the city where the energy will be stored using compressed air. At night, these sites will generate electricity for consumers. This technology is already available today: the PowerSouth Energy cooperative plant in the town of McIntosh, Alabama has been operating since 1991 (the white pipe blows air underground). The electricity that reaches the plant drives motors and compressors, and they compress air and flow it into underground caves, mines or aquifers. When the air is released, it is heated by burning small amounts of natural gas. The hot steam expands and spins turbines to generate electricity.

Large power plants operating through the concentration of solar energy will complement the photovoltaic farms in the southwestern United States. The power plant at Cramer Junction in the Mojave desert in California has been operating since 1989 using technology from the Israeli "Solel" company from Beit Shemesh. Parabolic metal mirrors focus the sunlight in the pipe and heat a liquid flowing through it, such as ethylene glycol. The rotating mirrors follow the sun. The hot liquid flows through the pipes, and inside the heat exchanger there is a loop containing water. The water turns into steam that drives a turbine. Future power plants will be able to flow the hot liquid into a storage tank where it will heat molten salt. This reservoir will be able to keep the heat to generate electricity in the heat exchanger at night.

And more on the subject

The Terawatt Challenge for Thin Film Photovoltaic. Ken Zweibel in Thin Film Solar Cells: Fabrication, Characterization and Applications. Edited by Jeff Poortmans and Vladimir Arkhipov. John Wiley & Sons, 2006.
Energy Autonomy: The Economic, Social and Technological Case for Renewable Energy. Hermann Scheer. Earthscan Publications, 2007.
Center for Life Cycle Analysis, Columbia University: www.clca.columbia.edu
The National Solar Radiation Data Base. National Renewable Energy Laboratory, 2007. http://rredc.nrel.gov/solar/old_data/nsrdb
The US Department of Energy Solar America Initiative: www1.eere.energy.gov/solar/solar_america

A large solar program - also for Israel

During the cold waves that hit us in January and February 2008, we learned that electricity consumption again reached very close to the red line of the electric company's maximum production capacity: 10,600 megawatts (assuming there are no production failures). It is safe to assume that the image will return even on hot summer days. Apparently, in the near term the electric company will have no choice but to build another coal-fired power plant, most likely in Ashkelon. One can risk and assume that the electricity company and the government will have difficulty passing the decision and will encounter vigorous opposition from environmental organizations, protests and demonstrations by the "greens", appeals to the High Court and the like.

However, with all the damage to the environment and increasing our share in greenhouse gas emissions, there will be no escape if we want to prevent the "darkening" of entire areas in our country during peak consumption hours. Today the electricity company has a production reserve that does not exceed only 5-4%. The rate of growth in electricity consumption is 3.5%-4% per year, which means that already in 2009 the reserve will drop to zero, and in 2010-2011 demand will significantly exceed production, which will cause damage to Israel's society and economy. The difficult situation we have reached in terms of electricity generation is even more evident if we compare it to other countries that are isolated like us in terms of electricity supply, such as Ireland, New Zealand and Iceland, where the electricity generation reserve is 30-25%. Among most of the countries within the OECD, which are not isolated (ie can receive electricity from neighboring countries), the reserve is about 15%.

Against this background, we have a special interest in the article by Ken Zwiebel, James Mason and Vasilis Patenakis entitled "The Great Solar Plan", published in this issue. The plan, which evoked widespread, mostly positive, echoes in the US, offers for the first time a comprehensive long-term master plan, based entirely on technologies available today. Its goal is to base most of the huge US energy economy on non-polluting renewable energy, mainly solar energy. The authors emphasize that the implementation of the plan will also contribute to reducing the emission of greenhouse gases, which has the effect of slowing down global warming to a considerable extent.

An important problem that must be carefully examined in such a large plan, a problem that will also face us, if and when we want to realize a similar plan in essence (not in scope) in Israel, is the size of the desert area needed to locate the solar systems to produce the necessary amount of energy. According to the plan, the electricity will be produced mainly from photovoltaic arrays. in the technology available today. To produce 3,000 gigawatts of electricity, which will need to be supplied, according to their estimation, to the US energy economy by the year 2050, an area of ​​about 80,000 square kilometers will be required. The authors show that there is no difficulty in locating an area of ​​this size in the deserts of the southwestern United States.

Will we face the problem of locating an area suitable for our needs in the Negev desert? There are no data on electricity production that will be required for Israel until the year 2050, however, according to the plan of the Ministry of National Infrastructures, the intention is to set the electricity production at 20,000 megawatts by the year 2020. Apparently, it seems that there is no difficulty in locating areas in the Negev for the location of the solar systems. The area of ​​the Negev is 12,500 square kilometers (about 60% of Israel's territory), but most of it is used for IDF training areas, nature reserves, and outline plans for settlements. In this situation, solar energy can only be one of the solutions from Israel's basket of energy sources in the future.

In the future, Israel's governments will face difficult decisions in the country's integration into the global clean energy economy. Even our oil-rich neighbors have recently begun to turn towards the research and development of alternative energies. The government of Abu Dhabi, for example, decided to invest 15 billion dollars in a project known as "Masder" under which the "greenest city in the world" will be built.

In preparation for the implementation of a large solar program in Israel, it will be necessary to carefully examine all aspects and all possibilities, including the formulation of ways and means to save energy, in industry, public buildings, educational institutions and private consumption. Carrying out a large solar project in Israel is possible and preferably one hour before.