Technology

CSP Today investigates the potential of Micro-CSP in localised industry-specific applications

CSP faces a number of challenges, of which costs related to its large scale are undoubtedly at the forefront, along with concerns relating to land and water availability. With the economy of scale necessitating high levels of investment, individual investment in the industry has largely been overshadowed by corporate reliance on government grants, subsidies and PPAs.

Is there room for micro-CSP alongside the macro-dominated CSP market? CSP Today speaks to Graham Provan from Global CSP, a privately funded start-up company specialising in turnkey low carbon solutions about the potential for private investment in CSP and the feasibility of micro-CSP for localised industries.

CSP Today: Graham Provan, you are the founder and developer of Global CSP, a company which specialises in micro-CSP seen particularly in the creation of the ‘Mini-Power Plant’. What does this project entail?

G.P: About two and a half years ago we brought together a team of engineers and physicists from across the world to develop a hybrid solar system using sealed parabolic troughs. It is a precision engineered captor with a double base. The base is separated from the lens by a 25mm cavity in which we’ve inserted an insulated blanket (made from metalized polyethylene terephthalate (MPET) first developed by NASA in 1964 for the US space programme and reflects up to 97% of radiated heat) that locks in the heat and prevents it from dissipating outside the base of the parabola improving the efficiency of the trough.

The units are mounted on precision engineered frames that are computer controlled and track the sun from east to west and north to south optimising solar capture. A large unit would consist of eight captors, 4m square, providing 32m square of sun exposure per frame.

In order to secure the reliability of energy supply in non-sunlight hours, the parabolic troughs are run on an Integrated Solar Combined Cycle (ISCC) basis with the preferred back up fuel being gas because of its relatively low carbon emissions, although it can work with a range of other fuels including biomass.

Currently to date we have built a 15KWh 0RC power plant for testing, we are now designing larger power units up to 70kWh. Our focus remains on developing micro-CSP plants, for larger power plants we have an agreement arranged with Ormat technologies who are world leaders in this industry.

CSP Today: How does the Mini- Power Plant differ from existing CSP plants? Do you see Micro-CSP going into competition with Macro-CSP?

GP:  Our system can be erected in difficult areas, rough terrain or mountain slopes. Unlike with large CSP plants, where issues of land availability have become a source of friction, the mini-power plants can be adapted to be placed anywhere because of the design. Our parabolas are delivered to site flat packed, easily transportable, light weight with an aerodynamic design for wind speeds, easily manufactured around the world.This allows the mini-power plants to be used for localised conditions, for example  for  medium size industries including the dairy industry, food manufacturers that have a power and or hot water requirement including  residential areas requiring off grid power.  

The fact that the troughs are sealed with a high transmission solar glass that provides protection against harsh climate conditions in areas where large scale CSP power plants may not be able to function. To generateelectricity there is no water requirement with our system as we use biodegradable oil direct to the generating plant. Where hot water is required an on-site supply must be available.

The nature of the mini-power plant differs from the macro-CSP plant making it more suitable for localised industry specific tasks, rather than being limited large scale electricity production for national grids (although it could be used to top up grid electricity supplies as all units are AC current derived).

CSP Today: One of the biggest criticisms of micro-CSP is the high costs involved in producing this technology. How do you plan to compete in this niche market?

G.P: The overall flexibility of our plant is a unique selling point: it can be erected anywhere, off grid, on any terrain thereby justifying a higher tariff. For example most islands in the world including the pacific islands generate energy with diesel fuel causing much higher tariffs than main land power. Micro-CSP can be highly competitive in this environment. Global CSP’s parabolas are flat packed requiring no welding and so reduce the skilled labour requirement, this allows us to manufacture in a competitive world market. In addition, the ORC units can also be used to generate waste heat from industry giving a greater economy of scale.

CSP Today: Your research and development activities have been focussed in New Zealand and France. Why have you chosen these areas?

GP: New Zealand runs from latitude 33 degrees at the top of North Island down to 45 at the bottom of South Island and has many Pacific Island dependencies searching for renewable energy solutions. It has clear skis which helps improve DNI levels. We have been studying proposals for the development of a science park in the North of the Island which is situated near a refinery, where we would absorb the waste heat burnt by the refinery and bring that into play with our solar energy to generate the amount of energy needed to run the solar park. I am also looking into building micro-CSP plants to work in conjunction with the dairy industry. New Zealand will be a study of the micro-market for the technology which can later be expanded to a global level. Our demonstration power plant for testing purposes is located in South West France.

CSP Today: What are the next steps for Global CSP and the Mini-Power Plant? And where do you see the micro-CSP industry progressing from here?

G.P: One of the biggest challenges facing Global CSP has been securing funding to develop the project further. As of yet, I have provided all the funding myself. What would be an ideal solution would be for the UK government to invest by way of a share stake in the company and when the private funds become available they can exit hopefully with a profit.  All of the manufacturing of the collector units has taken place in Northern England and transported to France for erection. I see no reason why the UK should not become a major developer of CSP technology and an exporter to a world market. Having built some land mark projects including the Concorde UK industries, Universities and Colleges are indeed capable of meeting this challenge.

For more on the project visit the website 

To respond to this article write to the editor, Jennifer Muirhead