Note: this article first appeared in Renewable Energy Focus November/December 2012. Click here for a free signup.
GE Energy, a company that helps consumers understand and manage energy usage, also explores new ways to deliver clean, renewable energy. A subsidiary division, GE Digital Energy, was developed as part of the global Smart Grid effort to modernise and optimise how the world generates, moves and consumes energy.
In its quest to innovate, GE Digital Energy submitted a project – Sustainable Energy Generation and Management for off-grid Remote Communities based on Smart Grid Technologies – to the 2011 Institution of Engineering and Technology (IET) Innovation Awards, for the Built Environment category. Centred on the implementation of an innovative power generation control and monitoring system, the project was tested by the remote off-grid community of Bella Coola in British Columbia, Canada and its ability to reduce its dependency on diesel power.
Demonstrating real social, economic and personal change as well as pioneering and sustainable thinking, GE Digital Energy walked away with the 2011 accolade. The project was a partnership between BC Hydro, General Electric and Powertech. It was supported by the province of British Columbia and Sustainable Development Technology Canada (SDTC), an arm's-length, non-for-profit corporation created by the Government of Canada.
The aim of the project was to demonstrate a more efficient and cost effective way of covering the energy requirements of an off-grid remote community. Bella Coola was selected due to its energy requirements being covered by local power generation resources – specifically, diesels and hydro-electric units. The lack of a water level controller and a storage device also means that renewable power is not efficiently used, leading to an excess operation of costly and polluting diesel units.
GE Digital Energy saw this as an opportunity to test its smart grid technology with the main objective of reducing the community's reliance on and consumption of diesel power and cutting the corresponding emission of greenhouse gases.
The project came about after some inventive brainstorming between Amir Hajimiragha, the Digital Energy lead application engineer, and his former colleague Mohammad Zadeh. It was formally launched in September 2010 with the monitoring system up and running for a long period of time thereafter.
Local controllers for diesel generators were successfully tested in June 2011 and after several months of running the whole system in Advisory mode to collect and analyse data, the water level and central controllers were finally tested in auto mode in November 2011.
This aimed to reduce the community's annual diesel consumption by an estimated total of up to 200,000 litres and lower greenhouse gas emissions by 600 tons annually.
Key to the project was the GE Digital Energy optimisation-based microgrid controller that automatically responded to changes in supply and demand so that energy is managed efficiently. By incorporating electric and hydrogen storage devices together with a variety of smart-grid technologies, the system made use of hydro units by storing energy as electricity or hydrogen during off-peak time periods and returning this to the system at optimal periods.
“A few necessary changes have been made along the way, mainly equipping the original operator dependant system with advanced technologies, to limit the risk of operator misjudgement,” comments Hajimiragha. “A variety of mathematical tools and technologies are now serving a vital technical need. As a result, we are confident that we can deliver a cleaner, more efficient power generation system that supplies the community with sustainable, more reliable energy.”
He adds: “It might seem quite obvious that the inclusion of the storage device either in the form of electricity or hydrogen could be a solution to the problems of this off-grid community; however, how to operate this storage device and make it interact with other generation units in the system in real time remained a challenging task.” GR Digital Energy's design and the resulting product addressed this challenge.
The impact on the 2000 residents has proved to be substantial. The ability of the product to operate in real time and in harsh weather conditions is an invaluable asset for the community. Initial factory test results showed that with the deployment of the storage devices and the optimisation based controller, the total operation costs on a typical summer's day could be reduced from $803 to $293 and estimated fuel savings could add up to 200,000 litres per year.
In early November 2011, the team reached another milestone when it successfully tested the major capabilities of the control system solution after several months of running it in advisory mode which bolstered the team's efforts to win at the 2011 IET Innovation Awards.
“GE Digital Energy has always been actively involved with the IET and as one of the largest institutions in the world, we felt recognition would be a significant milestone in this project by showcasing its achievements to an international and respected audience,” says Hajimiragha. “The knowledge and intelligence that we have had access to through the IET's engineering resources and contacts have been invaluable in a variety of projects that GE Digital Energy has and is continuing to develop.”
Based on the prior successful test of the system, long-lasting and substantial benefits at Bella Coola are expected. This is a promising future for our smart grid technology, which is not limited to just Bella Coola community,” claims Hajimiragha.
He comments: “With hundreds of off-grid communities around the world and as much as 44 per cent of the global population living in rural, sometimes remote areas, there is clearly huge potential for this kind of technology.”
Significantly, the system can be used with different power sources including solar and wind technologies, Hajimiragha says. “This system works fine with any kind of renewable power sources. In fact, any forecasted values for the hydro, wind, or solar should be provided. This can be done either by our central micro grid controller or it can be done by an external device.” If an external device is used, the forecasted values should be communicated to GE Digital Energy's central controller.
“The other important aspect of the developed system is that it supports operation of some particular renewable power sources that can run as isochronous machines to take care of the frequency. An example of such systems which happens to be the case of Bella Coola micro grid, is run-of-the-river hydro units with small reservoirs,” he concludes.
Thanks to the Institution of Engineering and Technology for their assistance in producing this article.