Spain’s auctions need a CSP quota say engineering experts

Steam Turbine Generators Synchronously Regulate Frequency In Solar Thermal Power

Engineers from CSP visited Abengoa's solar thermal energy project in Cerro Dominador, Chile while it was still being built.

COIIM Urges Launch Of CSP Quota Auctions For Solar Thermal Energy

In the field of power generation, Spain holds a prominent position worldwide, boasting advanced technology and capabilities in this area. Having 50 facilities set up from 2007 to 2013, Spain has been able to install a whopping 2,300 megawatts of power.

After that, the industry has been stuck in a stalemate in Spain until the Integrated National Energy and Climate Plan 2021-2030 (PNIEC) provided plans to deploy 5,000 MW of solar thermal energy by 2030. This initiative would provide Spain with around 7,303 MW of installed power capacity from solar thermal energy, which is thrice the present capacity.

Jaime Segarra, a professional from COIIM, stresses that the PNIEC specifically opted for this technology due to its storage potential, which allows for the provision of electricity to the system even during nighttime hours.

By adding more batteries with considerable capacity, photovoltaic facilities can also attain a comparable level of control. Yet, this comes with a price tag per unit of saved electrical power that is significantly more costly than the heat storage systems of solar thermal plants. These systems often use molten salt tanks to store heat.

According to the professionals from the College, it is essential to encourage the adoption of more effective advancements and plans that can bring about significant savings. One instance of this is the central tower technology, which is expected to become more feasible in terms of both technical and financial aspects, thanks to the latest auction initiative for solar thermal power plants. This development will enable the technology to become cost-competitive compared to the leading global counterparts.

The authorities have put in place a timetable of bidding opportunities to allocate the economic arrangement for sustainable energy. They have specified the least amounts of energy that must be generated for each technology between the years 2020 and 2025.

Nevertheless, the solar thermal minimum threshold was only 600 MW during that timeframe, with 200 MW being allocated for each year - 2021, 2023, and 2025. "Due to this timeline, it became almost impractical to accomplish the PNIEC goal of 5,000 MW by 2030. This is especially challenging taking into account the lengthy duration of executing solar thermal projects, which require at least three years to complete. Essentially, this would leave us with only two years (2026 and 2027) to commence projects to generate an overall capacity of 4,400 MW," as per Segarra's statement.

In October 2022, after a year of postponement, the Government announced an auction for power quotas that included reserved 200 MW for solar thermal technology.

Regrettably, there were no buyers for the solar thermal auction due to the bids being over the expected reserve or cutoff price. The exact prices that were bid have not been disclosed.

In order for the Government to meet its decarbonization goals outlined in the PNIEC, which includes adding 5,000 MW of solar thermal power with about 50 or 60 GWh of storage capacity, it may need to consider alternative options apart from building new solar thermal plants. A comparable solution could be replacing solar thermal power with an equivalent capacity of photovoltaic plants with additional battery or pumped storage to make up for the lack of solar thermal storage capacity.

Segarra has pointed out that in order to achieve the storage capacity planned in the PNIEC by 2030, which is 6000 MW, we may have to rely on batteries and pumped storage. However, this could result in higher costs per unit stored and possibly higher electricity generation costs during periods without sunlight. As a result, the overall projected average generation costs of the system in 2030 may increase.

An alternative solution could be placing greater emphasis on utilizing pre-existing combined-cycle gas power plants during periods of no sunshine. However, the expenses for electricity generation from these plants can be unforeseeable and incredibly expensive. Moreover, this approach could cause further issues if the EU commitments are not met.

"Benefits Of Solar Heat Power"

The College believes that the PNIEC's dedication to solar thermal energy is accurate, but the progress of this technology is too slow. Apart from the evident decrease in the cost of generating electricity, solar thermal plants offer many other benefits that set them apart from other options.

Spain would receive a greater proportion of added value from its investment expenses, compared to photovoltaic and battery plants. This would help to minimize the adverse effect of the significant investments needed in the balance of payments, which can then be balanced out by decreases in natural gas imports.

The placement of modern solar thermal plants in Spain, utilizing central tower technology, is expected to have a great impact on Spanish engineering and construction firms. This could position them as leaders in the worldwide market for this solar technology, which is still in the process of becoming commercially established.

Their steam turbine-powered synchronous generators have the natural ability to regulate frequency, which outperforms combined-cycle power plants in this particular aspect.

They are providing an option to use their extra storage space during autumn-winter or any day with minimal solar power to save surplus wind energy at a cheaper rate by employing resistors. This will help increase the overall storage space and ultimately improve the ability of the electrical system to manage energy supply, resulting in reduced average generation costs.

renewable energy sources that may not be available all the time. They could provide the option for future combination with gas turbines that work with H2, biomethane, or natural gas to guarantee consistent electrical power production even when relying solely on renewable energy sources that may not always be accessible.