Aug 3, 2015

Part 3: The science of new and old energy – renewable energy sources

Energy Digital Staff
3 min
Renewable energy sources are largely derived from solar energy either directly or indirectly. The most promising, thus far, include solar photovoltai...

Renewable energy sources are largely derived from solar energy either directly or indirectly. The most promising, thus far, include solar photovoltaic systems, wind power and hydroelectricity; however, new technologies such as hydrogen and fuel cells show tremendous promise as well. The North American Energy Infrastructure Act brought about an integrated power grid that enables the U.S. and Canada to share energy resources. Many of the projects underway take advantage of renewable energy technologies. The Soule River Hydroelectric Project, located in Alaska, will provide hydroelectric power to British Columbia and the U.S. Pacific Northwest. Montana-Alberta Tie Limited will generate power from wind farms.

The most highly developed solar energy technologies consist primarily of solar collectors and photovoltaic systems used to convert light to DC power. Photovoltaic systems include small, thin panels of semiconductors called solar or PV cells. A chemical reaction takes place in the solar cells upon exposure to sunlight that generates electrons to produce current. The solar cells are installed on large panels, some of which are designed to track the sunlight throughout the day. Other components of the PV system include one or more batteries, a charge regulator and a inverter that converts DC current to AC current. Solar PV has become a rapidly growing industry as the cost effectiveness has improved. It offers a clean, inexhaustible source of energy. Although at present, the technology is insufficient to meet the demand for energy, many utilities, organizations and residences use solar PV systems to supplement present energy sources and help reduce costs.

As of 2013, there were 46,000 operating wind turbines in the United States. Wind energy provides 4.1 percent of the energy produced in the nation. Wind turbines are equipped with blades that are rotated as the wind blows. A shaft that connects from the blades to a generator revolves as the blades turn to produce electricity. The primary objection to the technology stems from the fact that they require a large space to generate a significant amount of power.

Canada is the largest producer of hydroelectric power in the world. Its 450 hydroelectric stations produce 62 percent of its energy. In addition, there are presently 1756 hydroelectric power facilities in the United States. Hydroelectric power facilities are typically constructed on large rivers that have a significant drop in elevation. The damn retains large volumes of water in a reservoir. Gravity forces water through an intake near the bottom of the dam wall. A turbine propeller is turned by the force of the water. A shaft connects the propeller to a generator which converts the mechanical energy to electrical power.

The various methodologies employed in energy production in North American necessitate the assimilation of a wide range of resources. At present, the vast majority of energy sources rely on a generator to convert various forms of energy into electricity. A generator produces electricity by moving wire or a disc, usually made of copper, between magnetic poles. The power distribution system requires large numbers of power cables, transformers and circuit breakers; therefore, it too demands a substantial amount of resources. Each of these systems requires maintenance and periodic replacement of parts that must be calculated into the economic viability. The North American energy infrastructure encompasses an immense range of materials and technologies and will continue to expand in the coming years.

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May 13, 2021

All but two UK regions failing on school energy efficiency

Dominic Ellis
2 min
Yorkshire & the Humber and the North East are the only UK regions where schools have collectively reduced how much they spend on energy per pupil

Most schools are still "treading water" on implementing energy efficient technology, according to new analysis of Government data from eLight.

Yorkshire & the Humber and the North East are the only regions where schools have collectively reduced how much they spend on energy per pupil, cutting expenditure by 4.4% and 0.9% respectively. Every other region of England increased its average energy expenditure per pupil, with schools in Inner London doing so by as much as 23.5%.

According to The Carbon Trust, energy bills in UK schools amount to £543 million per year, with 50% of a school’s total electricity cost being lighting. If every school in the UK implemented any type of energy efficient technology, over £100 million could be saved each year.

Harvey Sinclair, CEO of eEnergy, eLight’s parent company, said the figures demonstrate an uncomfortable truth for the education sector – namely that most schools are still treading water on the implementation of energy efficient technology. Energy efficiency could make a huge difference to meeting net zero ambitions, but most schools are still lagging behind.

“The solutions exist, but they are not being deployed fast enough," he said. "For example, we’ve made great progress in upgrading schools to energy-efficient LED lighting, but with 80% of schools yet to make the switch, there’s an enormous opportunity to make a collective reduction in carbon footprint and save a lot of money on energy bills. Our model means the entire project is financed, doesn’t require any upfront expenditure, and repayments are more than covered by the energy savings made."

He said while it has worked with over 300 schools, most are still far too slow to commit. "We are urging them to act with greater urgency because climate change won’t wait, and the need for action gets more pressing every year. The education sector has an important part to play in that and pupils around the country expect their schools to do so – there is still a huge job to be done."

North Yorkshire County Council is benefiting from the Public Sector Decarbonisation Scheme, which has so far awarded nearly £1bn for energy efficiency and heat decarbonisation projects around the country, and Craven schools has reportedly made a successful £2m bid (click here).

The Department for Education has issued 13 tips for reducing energy and water use in schools.

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