Monthly Archives: August 2008

Twelve Industry Teams Partner with DOE to Advance Integration of Solar Energy Systems into Electrical Grid

DOE has selected 12 industry teams to participate in cost-shared cooperative agreements focusing on conceptual design of hardware components, and market analysis. These projects will help develop products that maximize the value of PV systems and offer consumers greater control of their electric consumption and costs:  

 Apollo Solar (Bethel, Conn.):  To develop advanced modular components for power conversion, energy storage, energy management, and a communications portal for residential-size solar electric systems.  The inverters, charge controllers, and energy management systems will be able to communicate with utility energy portals to implement the seamless two-way power flows of the future.

 

EMTEC (Dayton, Ohio) Emerson Network Power, Liebert Corporation, Hull and Associates, and Ohio State University: To develop large, three-phase, highly efficient, small footprint, advanced and innovative power conversion, energy storage and energy management components for commercial- and utility-scale PV systems.  The new products will include an integrated grid interface controller that works in conjunction with a customer smart meter to respond to time of day pricing signals.  The total system provides improved economics for power distribution and minimizes wide fluctuations in supply and demand of electricity.

 

Enphase Energy Inc. (Petaluma, Calif.): To develop a complete module-integrated solar electric solution controlled by an energy management system, to interface with utilities and allow advanced control for modular utility-interactive applications.

 

General Electric (Niskayuna, N.Y.) and Sentech, Inc. in collaboration with candidate utilities including American Electric Power, Duke, and Hawaii Electric Company:  To develop product concepts for integrating solar PV generation with the electrical grid for commercial and residential use. The residential improvements will integrate energy storage, responsive loads, and utility demand side management and are expected to reduce homeowner energy bills and support utility needs to reduce peak loads. New and enhanced inverter and distribution system control concepts for both commercial- and utility-scale installations will be developed. 

 

Nextek Power Systems (Detroit, Mich. and Hauppauge, N.Y.) with Houston Advanced Research Center: To modify an existing power gateway design to incorporate bi-directional current flow capability, higher voltage operation, and added functionalities that include integrated communications and an energy management system for value-added PV utility interconnections.

 

Petra Solar (Somerset, N.J.) with Florida Power Electronics Center, and Florida Solar Energy Center:  To focus on multi-layer control and communication with PV systems to achieve grid interconnectivity, cost reduction, system reliability, and safety – resulting in a cost competitive, easy to install, modular and scalable system.

 

Premium Power (North Reading, Mass.): To develop an inverter system that makes PV economically viable in terms of initial investment, operating costs, and system lifetime.  

An intelligent PV system that optimizes the value of PV generation will be developed for commercial- and utility-scale applications with an advanced inverter having energy management.

 

Princeton Power Systems (Princeton, N.J.) with TDI Power and World Water and Solar Technologies Corp.: To develop a complete design for a 100-kW demand response inverter based on Princeton Power Systems’ proprietary inverter technology.  The design will be optimized for low-cost, high-quality manufacture, and will integrate control capabilities including dynamic energy storage and demand response through load control.

 

PV Powered (Bend, Ore.) with Portland General Electric Team, South Dakota State University, and Northern Plains Power Technologies:  To develop a suite of maximum power point tracking algorithms to optimize energy production from the full range of available and emerging PV module technologies with communications integration, facility energy management systems and utility management networks.

 

SmartSpark Energy Systems, Inc. (Champaign, Ill.) with Evergreen Solar and Innovolt, Inc: To design, construct, test, and commercialize an alternating-current PV module with smart building systems interfaces that provide system diagnostics, data logging, and advanced utility interconnection.

 

The Florida Solar Energy Center of the University of Central Florida (Orlando, Fla.) with SatCon, Sentech, Inc., EnFlex, SunEdison, Northern Plains Power Technologies, Lakeland Electric Utilities and additional utilities: To develop new grid integration concepts for PV that incorporate optional battery storage, utility control, communication and monitoring functions, and building energy management systems. The Florida Solar Energy Center of the University of Central Florida will validate an anti-islanding strategy for PV inverters to allow PV generation to remain connected to the grid during some grid disturbances, while still meeting safety operation requirements. New inverter architectures with advanced controls will be introduced, bringing even more stability and security to the home. 

 

VPT Inc. (Blacksburg, Va.) with Center for Power Electronics, Plug-in Conversions, Moonlight Solar, Breakell Inc., and Delta Electronics: To develop component circuits and an overall system design for an integrated energy system.  The R&D will include inverter controllers that can be used with existing inverters to add sophisticated home interoperability, active anti-islanding and intentional islanding control, and a bidirectional power converter designed for plug-connected vehicles. The bidirectional power converter will also be useable for stationary DC/AC grid-interactive applications.

 

*** Editorial remark:  Beside the program of  General Electric, Sentech, American Electric Power, Duke, and Hawaii Electric Company (that by itself is not enough) – it seems that there is no real work plan that could develop a sustainable tachnology or family of technoogies for clean energy production with near zero emissions and more important to reduce our dependence on fussil fuels, and especially crude oil. The amount of money dedicated to these programs is a shame! The US can do better. Just take a strategic decision, like President Ronald Reagan took when he decided to destroy the evil ones of his era.

Thin film, printed electronics

Harry Zervos, Power Engineering

The advances in thin film photovoltaics coincide with a very exciting time in the field of electronics and electrics in general as new uses of established technologies (e.g. printing) are leading to the development of new components and products that are cheaper to manufacture, lighter, flexible, bendable, rollable etc. Projections indicate that the market for printed and potentially printed electronics will grow into a $47 billion market by 2018, with thin film photovoltaics (beyond conventional silicon technologies) accounting for approximately $12 billion of that market.

 

Recently, researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) announced that they have moved closer to creating a thin-film solar cell that can compete with the efficiency of the more common silicon-based solar cell. The CIGS thin-film solar cell recently reached 19.9 percent efficiency in testing at the lab, setting a new world record, as the NREL revealed on March 24th 2008.

 

This is still far from the highest efficiency achieved in July 2007 by a consortium of researchers led by the University of Delaware (42.8 percent efficiency using a novel technology that adds multiple innovations to a very high-performance crystalline silicon solar cell platform) but of course, there are big differences in the manufacturing costs of these two technologies as well as the potential fields of application for them.

 

Bravo – Ms. Vivienne Cox, head BP Alternative Energy unit

By Tom Bergin

 LONDON (Reuters) – Oil major BP (BP.L: Quote, Profile, Research) has decided against spinning off its investments in green and alternative energy and will instead try and boost the impact of the investments on its shares by giving analysts more data.

In February, Chief Executive Tony Hayward said BP’s shares had received little, if any, uplift from its investments in renewable energy, while these would be worth between $5 billion and $7 billion if they existed on a standalone basis.

“We’ve looked at IPO options and we’ve looked at partner options, we’ve looked at other options, but at this point we’ve decided to keep these businesses within BP,” Vivienne Cox, head of the Alternative Energy unit, told a conference call with analysts.

 Cox said further data on the units would be provided to investors and analysts in February next year, which she hoped would give greater financial transparency on the units.

 Some energy companies, mainly utilities, have partially floated their wind energy units to take advantage of strong investor interest and high stockmarket valuations for green energy assets.

 (Editing by Will Waterman)

highly efficient process for storing energy is the bottle neck for deploying renewable energy [1]

 

The latest demand for renewable energy sources in general, solar & wind in particular, raised again the need for feasible energy storage solutions. Solar power is currently a daytime-only energy source because storing extra solar energy for later use is prohibitively expensive and grossly inefficient. Wind energy is also dependent of sufficient wind power, which exists in many areas mainly at night time only.

 

Various storage solutions for solar power plants were and are being developed; most of them are based on thermal storage. Much effort is invested for developing storage for trough technology (since it requires lower temperatures, up to 400ºC). Usually phaze changes materials (PCM) are being used, since it enables higher density in the storage and minimal temperature losses between charge and discharge. The main problem is the low heat transfer (due to low thermal conductivity of the salts), and this affects directly the amount of power that could be extracted from the storage. 

Several research is being executed for developing enhanced solutions, mainly by enhancing the heat transfer between the salt and the heat transfer fluid (in the molten salt receiver/hot storage tank), reducing transient effects, optimization of the storage materials.

 

Various solar tower electricity generation systems were developed and the most advanced of them was installed and tested in California. This system, Solar Two, generated 10MW electricity using an eutectic molten nitrate salts mixture pumped and piped from a ground-based cold tank to a receiver mounted on the top of a tower. The hot salt from the receiver is then piped to a second, hot tank on the ground. In a secondary loop, the hot salt flows through a heat exchanger to generate steam and returns to the cold tank. The third loop includes the steam generator, which supplies steam to a steam turbine electricity generator. This plant was closed on 1999. Now Sener is trying to do something similar in Spain.

For the trough, – in Acciona’s Nevada plant, for example, there is no storage (only for about 30 minutes, that is achieved by the fluid that is in the pipes). On the other hand, at Andasol, – Flagsol (Solar Millenium’s subsidiary) together with ACS Cobra are developing thermal storage based on molten salt.

 

A simple, inexpensive, highly efficient process for storing energy is the bottle neck for deploying renewable energy for electricity base and peak load demands.

 

Later on we’ll discuss possible other energy storage options.