Solar thermal technology has failed to upgrade its niche technology status, with solar PV technology taking over the solar energy space with its ever falling costs and other advantages over solar thermal technology. While Solar thermal (CSP) technology was on an equal footing with solar PV a decade ago, now hardly anyone talks about CSP despite its inbuilt energy storage capabilities.

The large project size of a solar thermal plant and long gestation times have made it a difficult proposition.  The technology is also not as mature with an underdeveloped supply chain. The solar thermal technology faced another major jolt as CSP player Solar Reserve failed to get financing for its $650 million plant in Port August in Australia. The company had won the right to develop the plant in 2018 but could not manage to get financing to date.

Also, read Why is Australia Building An Expensive Solar Thermal Power 


The Australian government extended the timelines and supported the project but the developer failed to convince lenders about the feasibility of the technology leading to the cancellation of the project. Note, solar thermal technology has already faced numerous setbacks over the last few years with large projects in the USA being canceled and given to solar PV developers.

Read the advantages of Solar Thermal technology.

There are hardly any new solar thermal projects being developed globally. With lithium energy storage costs falling as fast as solar PV costs, the only advantage of CSP will also fully disappear in a few years. Solar plus lithium storage plants are already seeing commercial deployments in a number of places and are already vying to replace coal and gas power plants. The other major advantage of solar PV is that they can be developed in any size from 1 kW to 1,00,000 kW and do not require much time to get installed. This modularity of solar PV is a huge advantage. There is a massive ecosystem which has developed around the solar PV technology which makes it very tough for any new or old competitor of this technology to enter the solar market. It is like the video cassette market where VHS beat out Betamax. The video cassette player market was ultimately killed by the CD and DVD market and it is likely that some new technology such as thin film, organic cells may come up in the future to beat the silicon technology today. But solar thermal like Betamax is dead.

Solar Thermal – Australia

The South Australian government has given an approval for $650 million solar thermal plant to be built by USA company SolarResevere. This does not make any sense in my view, given that PV solar prices have touched new all times low with lithium battery storage also showing rapidly declining prices. This means that solar plus storage will become competitive with large-scale fossil fuel plants in a few years.

On the other hand, Australia will be spending a prodigious amount of money in building only 150 MW of power capacity. While a 150 MW PV solar capacity can be built for around $150 million these days, the solar thermal plant will cost more than 4x times. This is a gross waste of taxpayers’ money to build a technology that is not getting traction anywhere else in the world. Even the domestic market of SolarReserve has rejected this technology with almost all the new solar energy plants being built using the standard crystalline silicon PV technology. Even some of the solar thermal plants that were planned to be built in the USA earlier were abandoned and converted to solar PV plants.

Solar thermal plant

Also, read Why is Australia Wasting Money On A $650 Million+ Solar Plant Using A Failed Technology?

The solar thermal plant will also rely on a substantial federal loan for its development as the capital cost is quite high. The Australian power market is one of the most inefficient in the world with Australian consumers paying extremely high prices for electricity despite being blessed with huge and cheap resources of both renewable and fossil fuels. The wasteful market structure with a utility oligopoly has led to a situation where Australians will see their retrial power prices increase by another 10% next year on top of a 90% increase over the last decade. This solar thermal power plant will be further adding to the overall costs.

A recent auction by US utility Xcel found extremely cheap prices for solar plus storage and wind plus storage for power plants to come online by 2022. Factoring in declining prices of both solar energy and storage, a median price of just 3.6 cents was bid for new projects. Even wind plus storage costs were extremely cheap. Instead of allowing a solar thermal plant, the South Australian government should ask Xcel to conduct a similar auction in Australia. This will save the Australian consumers, hundreds of millions of dollars in costs.

“Wind came in lowest, at $18.10 per megawatt-hour. It was followed by combined wind and solar, at $19.90; then wind with battery storage, at $21; PV alone, at $29.50; then wind, solar and battery storage, at $30.60.

Wind also came out ahead in terms of generation volume, accounting for more than 42 gigawatts of bid proposals and 17 gigawatts of projects, compared to PV’s nearly 30 gigawatts of bids and 13+ gigawatts of project capacity.

PV was, nevertheless, the preferred option in terms of number of projects. Standalone solar was proposed in 152 bids and 75 projects. A further 87 bids and 59 projects were for solar-plus-storage. It remains to be see how many, if any, will be chosen.”

Source: Green Tech Media

New $5B Solar Thermal plant in California

For many years, we at Greenworldinvestor have forecasted the demise of the solar thermal technology and sure enough all the major startups in the solar thermal energy got bankrupt one by one. With the technology getting slaughtered by the rapid development of the solar PV technology whose costs declined dramatically. Solar thermal plants which can only be built on a large scale, require large amounts of capital and scarce resources like water. Now there is hardly any new large solar thermal plant getting built in the world, as the technology has become obsolete much like the Betamax technology in videos which got obsolete by VHS.

The cost decline of solar PV has become so dramatic that solar PV plus energy storage is now cheaper than solar Solar thermal plantthermal technology. However, this has not stopped a solar thermal company called Solar Reserve to dream about a $5 billion solar thermal project in California. The company which uses a power tower technology like Brightsource Energy wants to build a 2 GW project over 16000 acres of land. What I am surprised is the low cost that the company mentions $2.5 /watt, since its existing plant of 110 MW was built at nearly $10/watt. I do not think solar thermal technology has advanced so far to reduce costs to $2.5/watt.

Also read Is the failure of the Ivanpah the final death knell of the Solar Thermal technology?

Even at $2.5/watt the costs are probably too high since solar PV plants can be built at $1/watt in large utility scale sizes now. These costs will further go down to around 80 cents/watt or low, when this plant gets built (if it does). I think this solar thermal plant is a white elephant project that is most probably being thought to extract Federal subsidy dollars. The 110 MW plant that Solar Reserve built got a huge $737 million in subsidy dollars which is a massive waste of money in my view. Though that earlier plant got built in an era when solar PV technology was not that good, it might not have been a criminal expenditure. But now given that solar PV costs are so low and the energy storage is also going down in costs rapidly, this project does not make any sense at all.

A California-based energy company announced plans Tuesday to build the world’s largest solar project in Nevada, a $5 billion endeavor involving at least 100,000 mirrors and 10 towers as tall as any building in the state.

SolarReserve’s Sandstone project would include up to 10 concentrated solar arrays, each equipped with a molten salt system capable of storing the sun’s energy to generate power after dark, CEO Kevin Smith said.

The company already has built one such array, the 110-megawatt Crescent Dunes Solar Energy Plant, on 1,600 acres of federal land outside of Tonopah, 225 miles northwest of Las Vegas. The $1 billion array began delivering power to NV Energy late last year.


We at Greenworldinvestor had sounded the end of the solar thermal technology almost 3 years ago, when we had said the technology was no longer competitive with silicon solar PV technology. CSP technology which is based on solar thermal effect had many technology providers four to five years ago. At that time, the cost of solar PV was almost at par with solar thermal technology and both technologies were being used to build solar power plants. However as costs of silicon solar panel falls drastically each year, solar thermal technology started to look like an expensive hobby. Despite this, many countries such as USA and India continued to push solar thermal power plants through subsidies. But even as solar PV has become a mainstream energy source, solar thermal technology is still trying to find its feet.

While many solar thermal projects have been abandoned, some like Brightsouce Energy’s Ivanpah plant built at a cost of more than $2 billion got developed. However, many others were replaced with solar PV technology, as most solar thermal companies realized the massive cost advantages of solar PV compared to solar thermal. They were anyway fighting a losing battle.

Now the Ivanpah plant built by Brightsouce is running into trouble, as the power towers are failing to generate the required power as per the contract with Californian utilities. Brightsource plant may be shut down, if it fails to ramp up the power generation. Note power towers are niche technology and still in the conceptual stage. This is the first large plant built by Brightsouce and its failure would not be a totally unexpected outcome as a new technology takes time to stabilize. However, if Ivanpah fails, then it will be a major blow to solar thermal technology and it may not recover. Solar PV costs continue to decline making solar thermal look worse and even after 5 years, solar thermal technology is not expected to come close to solar PV costs.

With lithium battery costs expected to fall by 50% over the next 5-6 years, the only substantial advantage of solar thermal over solar PV will also evaporate. Currently solar thermal is able to store power through molten salts and oil, and supply power even at night which solar PV can’t do. But ubiquitous and cheap lithium batteries will make this advantage disappear.

Concentrating PV Technology

Concentrating PV Technology (CPV) is a niche solar technology in which mirrors are used to concentrate sun rays on high efficiency solar PV materials. This technology was supposed to have better potential than other technologies such as solar thermal technology, since it was built on the mainstream crystalline PV technology rather than competing with it. One of the world’s largest solar panel makers SunPower has already got a plan to advance its technology to use low power CPV technology.

However, some of the high power CPV technology companies are facing the heat. Some early entrants like Amonix has closed down a couple of years ago, but semi wafer maker Soitec has been pushing ahead its manufacturing plans based on some contracts it won in South Africa and USA. But now Soitec is facing major reversals as two of its contracts have been cancelled. Its plant in the USA now faces closure due to a lack of orders.

Soitec is now forecasting losses for the whole of the next year, due to the failure of its solar business take off in the last couple of years. Like many other companies, Soitec has been bruised by the cutthroat competition in the solar business which has exploded nearly 6 times in size over the last 5 years, becoming a $100 billion industry. However, the massive interventions by governments in solar manufacturing has made it a minefield for companies without significant backing. Even large companies such as Bosch and Siemens have exited the business due to low profitability and severe competition.

Soitec received a huge blow when one of its major USA clients Tenaska cancelled a 150 MW order for CPV cells made by Soitec in favor of normal PV solar panels. There were disagreements about how to share the technology risk between the supplier and the client, as well as problems in equipment dispatches. New technology and products have a learning curve, which is a problem in the solar industry because the mainstream silicon PV technology is seeing massive cost reductions almost continuously. This makes it almost impossible for new technologies to compete with silicon PV. The same thing has happened to numerous other solar startups such as Nansolar, Miasole, Solyndra and others. I think Soitec would do well if it gets out of this solar business now, before it becomes a fatality like the others.


In California, Soitec had sold to a large Energy Service provider 150 MW(AC) of Power Purchase Agreements (“PPAs”) with San Diego Gas & Electric (“SDG&E”) for a solar project under development in California (see press release dated October 23, 2014). Soitec has been informed by the new owner of the PPA contract that they are facing a major roadblock which prevents the project to materialize. Certain of the administrative conditions pertaining to the transaction could not be fulfilled timely. Soitec will therefore not receive the expected CPV systems order from the designated EPC contractor which was anticipated to leverage its US cost base.

Solar thermal technology has become a failed one, with solar PV taking over as the mainstream solar energy technology. Solar thermal companies have been going bankrupt at a rapid pace and solar thermal plants are being cancelled left, right and center. Some of the solar thermal plants are being converted into solar PV ones now. Brightsource which is one of the biggest solar thermal companies, has recently canceled its plan to build a massive solar thermal plant in California. Despite, a JV with Abengoa another large solar thermal company, the project was called off without any reasons being given.

Solar PV has seen an 80% fall in costs, as the technology has become a mainstream one. Solar PV plants are not being installed in as low as 3 months, compared to the 4-5 years that it takes a solar thermal plant to be built. There are hundreds of suppliers of solar PV components with the recent tender of a Dubai solar PV plant seeing interest from more than 40 suppliers. In comparison, Indian solar thermal plants are not being built as suppliers such as Siemens and others are leaving the solar thermal segment. The technology has become a failed one, despite its ability to easily store power. The costs for solar PV is now much much lower than solar thermal power and installation is also much faster.

Solar PV has become a global phenomenon, with solar PV plants being put up in most countries now. In comparison, decent solar thermal capacities exist only in a few countries such as USA and Spain. Even in these countries, solar thermal capacity addition has become glacial with Spain almost putting a stop to solar energy growth due to the massive boom in solar PV installations in 2008. USA is also going almost solar PV, with companies like Vivint and SolarCity becoming billion dollar solar PV residential installers. In comparison, Brightsouce has failed to do an IPO due to lack of interest.


The consortium of solar companies seeking to build a 500-megawatt solar power tower project in Riverside County has formally withdrawn the project’s application from consideration by the California Energy Commission.

The Palen Solar Electric Generating System had just received tentative approval from the Commission this month to build one of two planned 750-foot solar power towers in the eastern Chuckwalla Valley.

But on Friday afternoon, project owner Palen Solar Holdings formally withdrew its petition on behalf of the project, which likely means the project is dead — at least for the foreseeable future.