Alternative Energy: A Disruptive Technology?

Alternative energy, at first glance, appears to be far from disrupting our traditional sources of energy—oil, coal, gas and nuclear sources. In fact, according to British Petroleum’s Statistical Review of World Energy, alternative energy consumed has grown only slightly in the past 50 years, as evidenced by the green line in the graph that hovers only slightly above zero. However, in just the past couple of years, dramatic new trends are changing the alternative energy landscape.

By Martinburo (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons

Enerdata, an independent research and consulting firm specializing in the analysis and modeling of global energy markets, published its annual Global Energy Trends, 2017 edition in June. Among the G20 nations, the USA, the EU and China have all increased their production of renewable energy.

China, in particular, has made major adjustments in moving away from coal. Their wind power generation grew 30 percent in 2016 with a total of 52GW capacity installed in the past two years. China now accounts for one-fourth of wind power produced by all of the G20 nations. The USA, with its Production Tax Credit spurring investment in wind energy, has driven the deployment of 21GW capacity.

Wind energy may reach ten percent of the USA’s total energy production by 2020, according to the American Wind Energy Association.

The growth in solar energy once again finds China leading many other nations. In 2010, China represented only two percent of the G20’s solar energy production. Now, with 15GW of solar power deployed in 2015 and around 35GW in 2016, China accounts for a quarter of the G20’s solar production.

In the USA, the Solar Energy Industries Association and Green Tech Media report that 2016 saw a 39 percent increase in solar generating capacity, bringing solar to the number one source of new electric generating capacity for the year. Perhaps most dramatic of all reports covering solar, Dutch scientist Auke Hoekstra Tweeted the results of his research that compared annual projections by the International Energy Agency (IEA) with actual growth— which shows solar taking off at an almost hyperbolic rate, much faster than IEA forecasts.

The USA in 2016 produced just over 4 trillion kWh of electricity with about 15 percent coming from alternative, renewable sources. Coal, natural gas and nuclear accounted for almost 84 percent, with the balance from other sources, according to the U.S. Energy Information Administration. It’s becoming clear we need to stop thinking of renewable energy sources as “alternative.” They’re becoming more mainstream every year. With news of car makers moving to electric vehicles and entire nations reporting their plans to ban internal combustion vehicles in the next decade or so, renewables will continue to play a far more important role.

Renewables, by the Numbers

The U.S. government identifies five renewable energy sources that, together, account for 14.9 percent of electricity production as follows:  Hydropower 6.5%, Wind 5.6%, Biomass 1.5%, Solar 0.9%, Geothermal 0.4%.

In this article, let’s take a look at solar. However, let us also realize there’s more to solar power than the generation of electricity. Here, you’ll find a handful of solar energy applications that, while they may be less frequently discussed, are nevertheless important solar market niches poised for growth.

Solar Cooling

Using the power of the sun to cool a commercial or residential building seems counterintuitive, but there’s a growing market for solar air conditioners designed for a variety of applications.

Some use the power of the sun to generate electricity using photovoltaic (PV) cells. Solar A/C units are available for situations where there is no power available from the grid; where the entire system relies on a combination of solar power, coupled with batteries that power the A/C unit on cloudy days and at night.

Others, like HotSpot Energy units are designed for residential use. These hybrid units run on a combination of DC power from solar cells, augmented by 220VAC power from the grid when needed. Such units can provide both air conditioning and heat.

Another type of solar-powered A/C unit uses a desiccant. It needs no refrigerant or compressor. Desiccant materials have the chemical property of being able to attract and capture water vapor contained in air. These A/C units place a rotating wheel filled with desiccant in the incoming air flow where water vapor is removed. This drier air is passed to an evaporative cooler. When you test the wind direction by wetting your finger and holding it in the air, you’re using evaporative cooling. This process draws even more energy (heat) from the air. Ultimately, the unit passes cool, conditioned air into the living space. Some designs use a solar-powered heating coil to heat the desiccant and drive out moisture so it can be reused continuously.

Other solar A/C units use absorption chilling. Essentially, a solar collector heats a water and refrigerant solutions that drives the refrigeration process rather than a mechanical compressor. All of these solar A/C units can cut one’s commercial or residential electricity bill substantially.

Solar Space Heating

Active solar heating systems use the sun to heat water, propylene glycol or other liquids, which are delivered to insulated storage tanks and/or to heat exchangers for immediate use. Solar heating can produce hot water for bathing and laundry, as well as to heat the air inside a building.

For space heating, the process begins with a solar collector, the most common type known as a flat plate collector. It’s typically a black metal box with a glass or plastic cover. Sunlight passes through the cover to an absorber plate. Sunlight converts to heat which the plate passes to pipes that, in turn, convey heat to the liquid circulating inside. Space heating using solar energy is usually done via hot water baseboard heating, forced-air heating or radiant floors.

The electronics needed to manage and control a solar space heating system tends to be more complex than those for conventional oil, gas or electric systems. The solar space heating controllers need to manage any conventional backup system that might exist. It also needs to control sensors, motors, switches, heaters (to prevent freezing) and to monitor unexpected high temperatures in the collector system. For instance, a differential thermostat monitors the temperature differential between the liquid storage tanks and the solar collectors. When collector temperature increases beyond a certain threshold, pumps need to turn on so excess heat can be conducted to either the storage unit or the interior of the structure. On the other hand, if a lack of sunshine allows collector and storage unit temperatures to fall below a certain level, the control system needs to activate the conventional backup heating system. Learn more about solar heating at Energy.gov.

Solar Furnaces

Among the least-discussed applications for solar energy, solar furnaces hold a unique place in the alternative energy market. In fact, TMR Research published its Solar Furnace Market Global Industry Volume By Region (July 2017), [12] explaining that solar furnaces “…can be used for daily household tasks such as cooking. This could be a breakthrough for curbing pollution, especially if introduced in rural areas across emerging nations, as the technology would enable cooking without having to use firewood.”

A solar furnace uses a large number of mirrors to reflect sunlight onto a mirrored parabolic reflector. The heat energy available at the focal point of the reflector can reach 3,500 °C (6332 °F). Taking these extreme temperatures far beyond kitchen and back yard grilling, the world’s largest solar furnace in France uses its furnace to study the behavior of materials at extreme temperatures, heat transfer of fluid systems and high temperature physics of interest to the aerospace industry. Learn more about the World’s Largest Solar Furnace at Odeillo, France.

By H. Zell (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Quantum Dot Solar Cells

Not to be confused with research underway that’s destined to eventually bring quantum computing to the world, the use of the word “quantum” in the context of solar cells might have been borrowed to convey a sense of excitement about the tiniest of solar cells to date.

Traditional PV cells are sensitive to specific wavelengths of light. These quantum dot cells, manufactured on a nanometer scale and deposited on a network of crystals, can take on a range of sizes where each size can efficiently convert specific wavelengths into electrical current. By mixing sizes, a single quantum dot PV wafer can convert a wider spectrum of light to electrical current that conventional PV devices. Click here to learn more about quantum dot PV cells.

What Does Your  Project Need?

Natural sources of energy vary with the conditions of nature making power storage and conditioning a critical element to integrating these new “alternative sources”.  New England Wire offers technologies to help customers navigate the alternative energy landscape.  Flexible ropelays in a full range of sizes are regularly used to connect generating and conditioning equipment, as well as for grounding purposes.  Litz wire is often used in making extremely efficient inverters, and specialty highly compacted Litz is ideal for use in flywheel energy storage for grid stabilization, or power factor correction, and also in waste heat energy to electrical energy devices.

No matter what alternative energy industry segments you occupy, if your products use electricity and move electrons, New England Wire Technologies can help you. Our engineering and production teams design and manufacture one-of-a-kind wire and cable solutions for products and devices in the alternative energy space ranging from wireless charging and solar inverters, to wind power generation conversion systems and the ITER nuclear fusion project. We look forward to hearing from you and working together as your partner in powering innovation.