CSP on the roof: a MicroCSP revolution

February 16, 2010

The implementation of regulations for the production of clean energy in buildings could boost the development of a new market for micro-CSP technology.

Submitted by: ECOticias.com / Red / Agencies, 16.02.2010, 17:16 h

Additional information by Rikki Stancich

 Different regulations aimed at the creation of systems for generating clean energy in buildings, are being introduced in many countries as part of an overall strategy on energy efficiency.

 Given that 74% of U.S. electricity consumption occurs in buildings, it is not surprising that energy efficiency and renewable energy are essential criteria in establishing certification standards for clean building construction, including: LEED certification by the U.S. Green Building Council and the British BREEAM certification.

 This would open new market opportunities for a relatively new technology such as micro-CSP that could be used to generate clean energy in buildings.

  The micro-CSP technology can be used to generate electricity and as a heating or cooling system, being able to generate energy in a range from 75 KW to 20 MW.  Furthermore, due to its size can be installed in small areas such as the roof of a building.

 ”A roof of a small size, such as a shopping center, is sufficient to install the equipment micro-CSP,” says Darren Kimura, CEO of Honolulu-based company Sopogy Inc, which has developed a variety of micro-CSP systems.

 In the case of the technology developed by Sopogy, the operation of ORC (organic ranking cycle) is based on the temperature difference in a closed loop, rather than using steam.  Moreover, unlike the large-scale CSP technology, micro-CSP does not need such strict conditions of solar radiation and can be used in cities.

 This is thanks to the ORC system is not based on a steam turbine and therefore not affected by the decrease in solar radiation produced, for example, by the passage of a cloud that causes a drop in steam temperature and the resulting system malfunction.

 The French producer heat2power version also has its own micro-CSP technology, which uses a combustion engine instead of steam.

 The idea is similar to that of a conventional combustion engine with the difference that in this case the machine is fed with compressed air using an external heat source (air heated in a solar receiver to 1200 ° C) rather than fuel and by internal combustion.  The system uses a solar concentration mechanism in a point and refraction of radiation to a central receiver tower.

 Heat2power model can be produced in small sizes, generate 10 to 500 KW and used from a second hand engine single cylinder 0.5 liter to a large marine engines.

  Like the model Sopogy, heat2power technology can be used to heating, cooling or desalination.

 ”The roofs of industries are an ideal location for small-scale CSP technology.  There are no search costs of land and the system can provide chilled or electricity to the factory, “says Randolph Toom, heat2power director.

 This is important if one considers that in some regions the air conditioning is responsible for more than 50% of electricity consumption in buildings for periods of about 6 months.

 Generation of clean energy without neglecting finance

 The micro-CSP technology can aid the design of buildings cleaner because this system would reduce the consumption of fossil fuels for heating, cooling or power supply in buildings.

  Currently, both the LEED certification and other regulations, do not require the use of a specific clean technology.

  However, micro-CSP systems are presented as a very strong compared to other technologies so that builders can obtain such certifications.

 The LEED certification gives 7 points for a total of 110 points possible for the generation of renewable energy in the building.  The UK BREEAM certification also awards points for using renewable energy or produce low emissions of carbon dioxide.

 In this micro-CSP systems have advantages over other technologies such as solar photovoltaic panels.

  ”It emits more carbon dioxide in the manufacture of photovoltaic panels on the production of micro-CSP systems,” said Rajan Kasetti, Executive Director of the California company Terrafore Inc, a consulting firm on energy and technology in the sector renewable.

 Kasetti also asserts that while PV systems can cover 5-10% of the energy needs of a large building, micro-CSP technology on a roof can provide 30-40% of the required energy.

  Builders tend to avoid the use of systems of renewable energy generation due to the additional costs they pose.  However, should find micro-CSP technology very attractive if one considers that these systems have a shorter amortization period with respect to other options.  Kimura believes that for micro-CSP this period ranges from 3 to 7 years depending on the size of the project.

 ”The use of PV systems increases costs.  But not so with micro-CSP.  In fact, this technology increases the energy efficiency of the building, “says Kimura.

 This is demonstrated by a study of comparative efficiency in air conditioning systems.  The photovoltaic efficiency for these systems would be 9% while that could reach 40% with micro-CSP.

 Randolph Toom adds that the return on investment in the case of the model developed by heat2power is much faster than for other options.  “The approximate cost is about € 300/kw to heat2power system, compared with € 2000/kw of a sterling engine.”

 Furthermore, compared with other energy systems removable small-scale micro-CSP technology is more efficient and given its storage capacity is also a more stable option.

 ”By using micro-CSP can store heat that can be used later to generate electricity or steam in periods of low solar radiation,” notes Kasetti. “CSP technology is much more stable than photovoltaics, which is subject fluctuations, “adds Kasetti.

 Thrusters demand

 Supportive measures such as feed-in tariffs will play a key role in the growth and market penetration of micro-CSP technology.

 ”The proliferation of solar power has occurred in countries where there are favorable feed-in tariffs, such as in parts of Europe,” said Kasetti.

 The British government has recently introduced feed-in tariffs to encourage users and local communities to implement small-scale facilities clean energy production up to 5 MW.

 The British legislation allows users to achieve economic benefits through the installation of clean energy generation.  The government also plans next year’s introduction of measures to encourage the installation of the type of micro-CSP technology.

 These measures will undoubtedly mean a boost for the sector.

 The increase in demand for clean buildings for multinational companies committed since the environmental point of view also influence the expansion of micro-CSP industry.

 ”The builder will have a marketing advantage if the facility has systems for generating clean energy,” says Kasetti.

 But Kimura believes it will take at least five years before micro-CSP technology is commonly used in buildings.

 ”Our challenge now is to educate the public about the benefits of micro-CSP technology and explain that such systems are only usable in the desert and can also be used to generate steam and as cooling systems, “concludes Kimura.


Rooftop CSP: Greening the cities

February 11, 2010

Green building certification along with a host of demand-drivers may provide micro-CSP with critical market leverage.

By Rajesh Chhabara

Additional reporting by Rikki Stancich

Green building certification is gaining traction in many countries as a means of energy management.

With buildings accounting for some 74 percent of electricity use in the United States, it is hardly surprising that energy efficiency and use of renewable energy have become key criteria in green building certification standards such as US Green Building Council’s LEED certification and UK’s BREEAM certification.

As a relatively new product to market, micro CSP opens up new opportunities for buildings – green or otherwise – to efficiently generate on-site renewable energy.

A portable and scalable on-site solar energy solution, micro CSP can be used to generate electricity, as well as to provide heating and cooling. Suitable for generating energy in the range of 75 KW to 20 MW, micro CSP’s size means the system can be installed in a small area – including on the rooftop of a building.

 “A small rooftop, for example the roof top of a large box store such as Wal-Mart, is sufficient to install the micro CSP system,” says Darren Kimura, chief executive of Honolulu-based Sopogy Inc, which has developed a range of micro CSP solutions.

In Sopogy’s case, the micro version runs of an organic ranking cycle (ORC), which instead of using steam, uses the temperature difference between fluids in a closed loop. Unlike large-scale CSP, which requires desert-like conditions of perfect direct normal irradiation, Sopogy’s micro CSP can operate in or near cities.

This is because the ORC is less vulnerable than plants running off a steam turbine, where a cloud passing overhead can cause the steam temperature to drop and the system to shut down.

France-based technology developer, heat2power, has come up with its own version of micro CSP, which uses CSP to power traditional cylinder engines rather than steam turbines or Stirling engines.

The concept is similar to that of a standard combustion engine, except the engine is powered by compressed air, using an external heat source (air heated on a solar receiver to around 900 – 1200°C) rather than from fuel creating an internal combustion.

Using a point concentrating solar array to reflect light and heat to a central receiver tower, the heat2power model is scalable and can utilise anything from a single cylinder 0.5 litre engine to large marine engines based on marine engine blocks, generating power from 10KW – 5MW.

An added advantage is that the engine runs in an ‘open cycle’ and therefore does not require cooling towers or expensive dry cooling used for condensing steam.

Like Sopogy’s solution,  heat2power’s captures the waste heat, which can then be used for heating, cooling and desalination.

“Factory roof tops are the ideal place for small scale CSP. It doesn’t require purchase of land and the shade of the mirrors lowers the cooling requirements of the building underneath“ says Randolph Toom, managing director of heat2power. 

This is significant, given that in many regions air-conditioning can account for more than 50 percent of the electrical usage in buildings over a six-month period.

Greening the city, not breaking the bank

Micro CSP can help take green building standards to the next level, given that the system reduces the use of fossil fuel to heat, cool and power buildings.

Currently, LEED and other green certification systems do not require specific renewable technology, nor do they standardise energy systems.

However, compared to other options on the table, micro CSP promises to significantly help builders achieve points for certification.

LEED certification currently allows up to seven points for on-site renewable energy, out of the total 110 points possible. BREEAM, UK’s green building certification standard also awards points for the use of low carbon energy and renewable energy.

Here, micro CSP has an advantage over other similar-scale solar products such as photovoltaic panels.

“More carbon is emitted during manufacturing of PV panels than in making micro CSP system,” says Rajan Kasetti, chief executive of California-based Terrafore Inc, a renewable energy consulting and technology firm.

Kasetti also notes that while PV technology may be good for meeting 5-10 percent of a large building’s energy needs, micro CSP on the rooftop can provide 30-40 percent of the energy needed.

Builders, who often cite increased cost of adding renewable energy system as a reason for avoiding them, will find micro CSP’s shorter payback period very attractive. Kimura estimates the payback to range from three to seven years, depending on project size.

“If you use photovoltaic, it does increase the cost. But solar thermal cooling does not. It actually makes the overall building more efficient,” says Kimura.

This is demonstrated via an efficiency comparison in the case of air-conditioning. Photovoltaic efficiency is around 9 percent, compared to solar thermal efficiency, which can be as high as 40 percent. 

Toom similarly notes that the return on investment on the heat2power CSP solution is much faster than for other solar options.

“The cost is roughly €300/kw (US$407/kw) for a heat2power engine, compared with around €2000/kw (US$2,712/kw)  for a Stirling engine or €1000/kw (US$1,356/kw) for a steam turbine,” he says.

Compared to other small-scale renewable energy options, micro CSP is a more efficient and, given its capacity for storage, a more stable option.

 “Using micro CSP, heat can be stored which then can be used to generate power or steam when the load is higher in the evening or when the sky is cloudy,” points out Kasetti.  “CSP is also much more stable than the PV which is subject to fluctuations,” he adds.

Demand drivers

Support policies such as feed-in tariffs will play an important role in increasing the market penetration of distributed generation systems such as micro CSP.

“Solar energy proliferation has happened in countries where there are good feed-in tariffs as in some parts of Europe,” notes Kasetti.

The UK government recently introduced a feed-in tariff scheme to encourage households and local communities to set up small-scale clean energy generation of up to 5 MW.

The UK’s scheme enables households to earn money by installing low carbon electricity generation. The government also plans to introduce renewable heat incentive for installing micro combined heat and power next year.

Such policies, if adopted elsewhere, will undoubtedly boost renewable micro-generation technologies such as micro-CSP.

Increasing demand for green buildings from sustainability-committed multinational companies will also expand the number of micro CSP installations.

“The builder has a marketing advantage if the building is fitted with on-site renewable energy,” says Kasetti.

But Kimura estimates it will take about five years before micro CSP becomes commonplace in buildings.

“Most other CSP companies are selling utility scale power projects. For us, the challenge is in educating people about the benefits of micro CSP and explaining that CSP is not just for the middle of desert and that it can actually be used for generating steam and cooling as well,” he concludes.

To respond to this article, please write to:

Rajesh Chhabara: rajesh.chhabara@csrworks.com

Or write to the editor:

Rikki Stancich: rstancich@gmail.com

Furlough Friday at Sopogy

February 5, 2010


DATE & TIME: The workshop will be held on Friday, March 12th from 8:30 a.m. to 2:30 p.m.

LOCATION: The Sopogy headquarters at 2660 Waiwai Loop. We will meet at the Sopogy building at 8:15am. Sopogy will be implementing their “Fossil Fuel Free Friday” so all employees, staff, students, and participants are encouraged to attend using an efficient alternative mode of transportation such as walking, bike, bus, or carpool.

EVENT: The workshop is free of charge and open to high school students, especially for those students interested in science, technology, sustainability, and entrepreneurship. Students will take a tour of the facilities, learn about Sopogy’s MicroCSP technology, find out how Energy Industries uses proven technologies to innovatively lower electricity demand, have a discussion with CEO and founder of Sopogy and Energy Industries Darren Kimura, and perform an experimental CSP project using pizza boxes and tin foil to make smores. HiSciTech CEO Keiki-Pua Dancil and Kanu Hawaii Executive Director James Koshiba will be on hand as special guests to discuss the significance of technology and sustainability. Lunch will be provided.As space is limited interested students should respond as soon as possible to reserve a spot and come prepared with an open mind and a passion to learn something new.

To reserve a spot or for more information please contact:

John Rankin           (808) 265-8715  jtrankin@gmail.com

Rechung Fujihira      (808) 840-7337  rechung.fujihira@gmail.com

Special thanks to Round Table Pizza Kailua, Waialua Soda Works, and Styrophobia for providing lunch.

Darren Kimura CEO of Sopogy

Become a Sopogy Facebook Friend at: http://www.facebook.com/?ref=logo#!/pages/Sopogy-Inc/57390177523?ref=ts