|Jayesh Goyal of AREVA Solar|
Solar energy has thrived in recent years because of innovation in technology and business growth strategies. These strategies include power purchase agreements that let end users defray the costs of an initial upfront investment, component manufacturer partnerships that streamline solar integration, and even at the residential level where online purchasing options have made the process of going solar easier. One such growth strategy in the concentrated solar power (CSP) sector is the use of solar ‘booster’ and hybrid plants.
Analysts expect that over the next decade there will be a 20-fold increase in CSP generation, and the ability to pair CSP with fossil fuels will be key to this growth. Adding a booster to an existing facility is a cost-effective way to improve a plant’s performance and avoid or lower its emissions. CSP boosters can also provide grid stability in places with inadequate electric infrastructure. August’s blackout in India left more than 600 million people without power. CSP is a good fit for the Indian subcontinent because of the region’s high level of solar irradiation coupled with a growing demand for energy. And CSP augmentation can help address India’s lack of available coal and high natural gas prices, which are necessitating new, lower-cost solutions to increase output.
How solar augmentation works
Solar power augmentation is the result of utilities integrating CSP boosters into the steam cycle of existing fossil fuel, geothermal and biomass plants. With a hybrid, both a solar thermal facility and a new natural gas combined-cycle backup plant are built side-by-side and integrated. Utilities choose these types of CSP installations out of a need either to cleanly boost output to meet demand without added emissions or to offset fossil fuel consumption and cut multiple pollutants.
In several international energy markets, booster plants offer the opportunity to help meet sustainability goals, address the growing worldwide demand for energy and help contend with electricity shortages. CSP boosters and hybrids allow power generators to quickly bridge the carbon gap and bring their facilities in line with environmental regulations and sustainability goals.
Because the high-pressure superheated steam of many CSP solutions readily and quickly integrates into the steam cycle of existing plants, most boosters can be built in nine months or less. And by leveraging existing power infrastructure, booster deployment can result in a levelised cost of electricity that is significantly lower than similarly sized photovoltaic (PV) plants. Another advantage over PV and other renewable resources is that CSP steam generators for augmentation have enough solar thermal inertia to continue generating power during periods of intermittent cloud coverage. Booster projects, as well as standalone CSP plants, can also drive local economic growth. From 60 per cent to 95 per cent of the content used for CSP plants – mainly steel, concrete and glass – can be locally sourced. In southern Africa, the region’s economy has benefited from the creation and growth of a local industry through the construction of CSP installations. Projects there are expected to create 1827 construction and 120 operations jobs and $70 billion will be spent in local content with additional manufacturing jobs.
Real-world case studies
CSP booster projects are sprouting across the globe because of these benefits to utilities and other power producers. Egypt, Morocco and Algeria are seeing how CSP boosters can help meet growing domestic energy demands reliably and cost-effectively, while saving one of the region’s most valuable exports: oil and gas. Rather than use reserves domestically for electricity generation, many oil and gas-producing North African and Middle Eastern countries are finding it economically favourable to sell these commodities on the international market and leverage CSP for power generation at home. Saudi Arabia’s recent landmark plan to install a solar capacity of 41 GW by 2032, of which 25 GW is contributed by CSP, makes the case in point.
|CSP technologies like AREVA Solar’s Compact Linear Fresnel Reflector (CLFR) technology can generate superheated steam to efficiently boost traditional power plant output without added fuel costs or increased emissions.
Source: AREVA Solar
The potential for growth in booster as well as standalone projects is enormous. For instance, following the Arab Spring, the Egyptian New Renewable Energy Authority defined a bold target of satisfying 20 per cent of the electric energy demand from renewable energy resources by 2020, and at least 110 MW is designated for CSP, including both integrated solar-combined cycle and standalone CSP plants with storage.
North Africa is already home to 70 MW of installed CSP capacity integrated into 760 MW of combined-cycle power plants. A 150 MW hybrid solar trough gas plant (featuring a 20 MW solar element) was built in Algeria in 2011, making it the country’s first. There could be up to 10 GW of CSP installed capacity on the African continent by 2020. In terms of emission reductions, the 70 MW of installed CSP boosters produces roughly 140 GWhe per year of clean electricity, therefore avoiding approximately 50 000 tonnes of CO2 equivalent per year.
For the southern Africa region, which is predominantly powered by coal plants as well as combined-cycle plants, it is estimated that during the next decade CSP boosters can provide up to 1.5 GW of additional market capacity. Because CSP boosters can be installed as quickly as nine months, they provide a quick-to-market, cost-competitive and reliable energy resource to offset energy shortages and help meet growing demand.
In Australia, AREVA Solar is currently constructing a 44 MW Compact Linear Fresnel Reflector solar thermal addition to CS Energy’s 750 MW coal fired Kogan Creek Power Station. This installation in Queensland will augment the plant’s feedwater system, increasing the station’s electrical output and fuel efficiency. It will avoid approximately 35 600 tonnes of CO2 annually. When completed, this facility will be the world’s largest CSP integration with a coal fired power plant.
A gateway to standalone CSP
Aside from the benefits booster and hybrid projects offer to power customers, they are also important proof points to CSP industry players themselves. Convincing customers to make a sizeable investment, at a time of limited capital resources, can be challenging. A successful hybrid or booster project effectively demonstrates the reliability of a CSP company’s technology and its ability to deliver its project. This leads to a natural progression of utility customers choosing standalone CSP plants. South Africa is home to the Khi Solar One, KaXu Solar and Bokpoort standalone CSP projects that are currently under development by major CSP consortiums. When complete, the three plants combined will generate 200 MW of electricity.
Additionally, CSP providers have developed molten salt storage systems to meet the needs of utilities that require energy storage as part of CSP plants. These systems are already being proven in Spain and the US to help limit intermittency and improve grid stability. And these systems complement dispatchable, cost-effective solar/natural gas hybrid plants and solar augmentation of existing fossil fueled plants.
In short, growth in the global market for booster projects as well as the general wider adoption of CSP technology will help bridge the carbon gap, be a source of local jobs and economic growth and meet energy demand in regions around the world.
Jayesh Goyal is vice president, Global Sales. For more information visit www.areva.com