Education

Building self sufficiency

 By Nicholas Newman

Increasingly we are seeing more and more buildings producing their own power to provide internal heat and power, but also export power to the grid. It is becoming common practice for new and old buildings including offices, shopping centres, factories and homes to provide some or all their own power, through the installation of roof top solar panels, micro hydro schemes, onsite generators fueled by gas. In fact,the new Rabobank headquarters building in Eindhoven, in the Netherlands is set to become the world’s first building to be fitted with electricity-generating windows to provide power to charge employees phones, laptops etc. Nicholas Newman looks at the ways buildings are becoming more self sufficient in meeting their power needs…

Nissan Solar Farm in Sunderland, UK

For millennia, people have harnessed fire, water and wind to heat, light or cool their buildings. Flour mills, water-driven or wind-powered, are probably the most ancient of man’s alliance with the elements. The industrial revolution brought greater scale to this self-power generation, as seen in the textile mills whose looms were driven by water and later by steam. Today, thanks to a more sophisticated range of technologies, there are many more buildings, both old and new, generating their own power for heating, lighting and cooling, with any surplus being sold to the grid.

With new building codes and the incentive of relatively high feed-in tariffs, many new and even some old buildings can be routinely equipped to generate some or all of their power needs from solar panels, wind turbines, mini-hydro and on-site generators. As Steve Dunne, managing director of Group Savvy says, “a block of student flats I am building in Oxford is fitted as standard with rooftop solar and a range of energy-saving gadgets.” This example of power needs now being met off-grid can be widely replicated across much of the developing world.

Solar panels

Solar panels on the rooftops of residential, civic and commercial buildings have become quite common. Residential Rooftop PV systems provide between 5 to 20 kilowatts (kW); those mounted on commercial buildings, often reach 100 kilowatts or more. For instance, the roof of Nissan’s largest car factory in Europe, located in Sunderland, England, is fitted with 4,750 kw of solar panels.

While rooftops are the oldest location for sun-powered building devices, a new spot is being tried for the new Rabobank headquarters building in Eindhoven, Holland. This is set to become one of the world’s first building to be fitted with electricity-generating windows to charge the office’s phones, laptops and tablets. Essentially, the windows are covered with a transparent luminescent coating that converts the 30% of light reflected from the surface into invisible light that travels through the glass into the window frame, where solar cells convert it into electricity.

Dutch company PHYSEE is producing fully transparent and colorless windows that generate electricity

Micro-hydro schemes

For owners of buildings with access to rivers or streams, improvements in technology and incentives have made micro-hydro schemes more attractive. Typical schemes can produce between about 5 kW to 10,000 MW. To bring this into perspective, a 5kW system would create 4,500 kW, which is enough to power a 3-bedroom house in the UK for a year, estimates the Energy Saving Trust.

Blenheim Palace, one of the largest buildings in the UK, has begun to generate its own power from water. Among its extensive parklands, estate managers have installed a 15 kW closed micro-hydro scheme, the Compact Archimedean Screw system, supplied by Hallidays Hydropower. Highly efficient, the scheme’s turbine is designed to utilize up to 87 percent of the energy produced from the falling water. The Duke of Marlborough, owner of Blenheim Palace, stated that “I believe in the importance of creating and using sustainable energy, for the good of the environment and to support the running of this great estate. This scheme will reduce carbon emissions by more than 42,000 kgs (93,000 lbs) a year and provide the estate with a financial benefit worth around $28,000 – $38,000 per annum.

Wind power

Companies ranging from car manufacturer BMW, to washing machine maker Whirlpool are using nearby wind farms to provide electricity for their factories. For example, at Whirlpool’s Findley Factory in Ohio, an $18 million onsite wind farm was installed to meet 22 percent of the factory’s power needs. Each turbine is expected to generate electricity equivalent to the amount required to power 300-400 average sized homes.

Hallidays Hydropower installed an Archimedes screw turbine within Bladon Dam, which is situated on the Blenheim Palace Estate, in July 2014

Onsite generators

In many developing countries, owing to the unreliability of power supplies, businesses and even the richer households have invested in their own expensive diesel onsite generators. Given South Africa’s chronic power shortages, the country’s large industrial chemicals company SASOL, has gone one step further with its decision to invest in its own 140 MW gas- fired power plant. While it is commonplace in countries across Africa for businesses to rely on their own generators, these machines are becoming increasingly popular in more developed countries with the aim of maintaining supplies and cutting costs.

There are a range of fuels available for power generators including fuel cells, biomass, natural gas, geothermal and many others. A British supermarket chain, Sainsbury’s, has installed a geothermal heat pump at its Crayford store in Kent. This technology is expected to cut the store’s energy bills by around 30%, and has the potential to revolutionize supermarkets’ approach to thermal energy use across the world. The technology known as “geoexchange” uses a series of closed loop boreholes drilled 200 m (656 ft) underground to access natural heat from within the Earth. The boreholes will capture and store waste heat, which will later be released to provide heating, hot water and cooling for refrigeration on demand.

In Oxford, the University Hospital Trust is aiming to create a district heating and power system to both heat and power its extensive complex of buildings. This involves the installation of a new gas-fired Combined Heat and Power (CHP) unit, together with related pipeline and cable network infrastructure. Once completed, this $21.8 million investment is expected to save $676,000 every year for up to 25 years and will cut the Trust’s CO2 emissions by 30%, the equivalent of taking 3,000 cars off local roads every year.

Conclusion

Despite increasing adoption of schemes to make buildings more energy self-sufficient, many of these solutions are often not suited to old buildings, which remain the majority of structures in Europe. At this stage of development, the innovators behind these new technologies are still struggling to deliver more affordable products that comply with on-going improvements in building codes. In addition, at least in the UK, “builders in all sectors of the industry are facing a skills shortage in these boom times, but especially in the installation of new technologies,“ says Dunne. Providing such affordable solutions is proving challenging and the field is wide open for innovation.

about the author
Nicholas Newman
Freelance energy journalist and copywriter who regularly writes for AFRELEC, Economist, Energy World, EER, Petroleum Review, PGJ, E&P, Oil Review Africa, Oil Review Middle East. Shale Gas Guide. https://nicholasnewman.contently.com/