5 August 2014 — A trigeneration system that can be run off raw plant oils and featuring storage and demand management technology could have potential application in off-grid homes and businesses, as well as in developing countries, UK researchers say.
The system, developed by a consortium led by England’s Newcastle University, provides cooling, heat and power, and has been designed to provide electricity without the need for a mains connection through the incorporation of an advanced electrical storage system.
“The challenge was to design a system that could simultaneously satisfy the more predictable needs for heating and hot water, as well as the wildly varying demand for electricity in a small dwelling,” Newcastle University Professor Tony Roskilly said.
“Our solution was to incorporate advanced electrical storage into the system – both batteries and the latest supercapacitors – combined with [an] innovative system control.”
While traditionally trigen works well on large scales, in small premises turning on a pump or a kettle can increase the electrical load several fold in a matter of seconds, and attempts to match the competing demands of electricity and heat can undermine the unit’s efficiency.
The solution developed by the consortium was a generator running constantly at high efficiency, coupled to an electrical storage system so sharp peaks in electrical demand could be matched.
“Energy storage unlocks the key to the most efficient use of the trigeneration system,” Professor Roskilly said.
To make the system more sustainable – and more appropriate for developing world application – the team showed that the system can be powered by biofuels.
“We wanted to avoid running the trigeneration system using biodiesel or other highly-processed fuels from raw materials,” Professor Roskilly said. “So instead, we developed a system for using the oils obtained from pressing crop seeds, like those from jatropha and croton.
“These crops can grow in harsh environments and on poor-quality land and so could be well-suited to providing fuel in developing countries, as cultivating them would not adversely affect food production.
“The potential demand for this technology in such countries is very large.”