Day: November 8, 2017

Spurred by the economics and politics of oil, the high cost of coal, and the threats of global warming, there has been a big push for renewable energy. Traditional renewable energy sources like geothermal and hydroelectric are no longer enough, and now the push is for more wind, solar, tidal and wave energy generation.

Among these bold ideas for power sources, solar energy has been the most promising. Today, the landscape is changing for solar energy with countries like Germany and China leading the way in energy generation. Solar energy lends itself not just to large scale projects, but also for residences and office buildings. In some areas, there are prosumer programs where excess energy generated by the home is sold back to the electric utility.

This is good news for solar energy, as well as for renewables in general. There are more power plants under construction, and new technologies in the pipeline. However, there is a fundamental problem with the numbers being used to compare energy generation sources.

We Need More and Varied Sources of Power

Energy production plants are usually rated according to their capacity. The installed capacity is in kilowatts. In contrast, consumption is in kilowatt hours. This is where energy sources differ. A solar plant may have a certain capacity, but in terms of the power it supplies, it lags compared to other sources. A nuclear power plant may deliver up to 90% of its rated capacity, while a solar energy plant can only deliver up to 12%.

 

The world has 224,684 megawatts (MW) solar energy installed capacity, with a resulting energy output of 253,593 gigawatt hours (GWh) per annum, which is equivalent to 11%. Germany, which is a leader in solar energy generation, has a capacity of 39,784 MW with an energy output of 36,056 GWh, equivalent to a factor of 10.3%.

One of the causes of this is the intermittency of solar energy. Plants cannot generate power when the sun is down. This is also true for wind and tidal energy, as there are conditions when these sources cannot generate energy. The use of batteries can only help in supplying energy after dark, but not in generating power.

Solar as well as wind turbines can help consumers as they generate power for their own use. However, for the future, there would still be other needs which would require more energy production from centralized sources. As countries become more affluent, they would be using more energy. In addition, due to global warming, there is more need for air conditioning. These are pressures on the energy grid which have to be addressed accordingly.

Centralized energy production and transmission will not go away anytime soon. Even if home power generation becomes the norm, there will still be a need for a large central power plant to serve the community. It is estimated that by 2050, there would be 9 to 10 billion people on earth. Today’s urbanized centers will be more crowded than ever before, and there is not enough space to place the required solar and wind generation plants to service the requirements of these urban centers.

The percentage of renewable power supply would grow, but so would other large energy systems like hydroelectric, geothermal, and nuclear power plants. The energy these centralized big plants would generate would help feed the increasing demand. A diversified energy platform would happen due to the need to meet demand and this would leave a bold impact on the world’s energy supply.

Dyson is a UK consumer appliance brand well known for its wireless electric vacuum cleaner. The company is privately held and is run by its founder, inventor James Dyson. However, it is not a secret that he has been interested in developing clean energy automobiles since 1998.

With the acquisition of Sakti3, a pioneering battery research and development company operating out of Michigan, Dyson is poised to develop and manufacture a bold new electric vehicle (EVs) with lots of power in the battery.

Sakti3 is headed by Dr. Ann Marie Sastry, formerly of the University of Michigan. The technologies and patents which were developed by Sastry have more than doubled the capacity of lithium-ion (Li-ion) batteries. Although not yet in mass production, the Sakti3 batteries are solid-state lithium-ion batteries which produce over 400 watt-hours per kilogram (Wh/kg) energy density.

In contrast, current industry leader Panasonic batteries used by Tesla are rated at around 240Wh/kg. Recently, the company announced that they have tested a battery that has a specific density of 1143 watt-hours per liter (Wh/L).

The effective output of the Sakti3 batteries is nearing the point where the operating costs of electric vehicles start to approach those of gasoline- and diesel-powered conventional cars. Once the batteries become more powerful, EV operating costs would be cheaper than conventional cars, and this would make EVs mainstream vehicle choices.

Better, Improved Batteries

The Sakti3 batteries were designed to be improvements in current technology and deliver 2 to 3 times the energy density of conventional lithium-ion batteries. The key to the technology is the replacement of the liquid electrolyte with a solid material. This would be a thin film that separates the anode and the cathode. The three parts of the battery are the cathode, anode and the electrolyte between them. During operation, or discharging, the ions pass from the anode through the electrolytes going to the cathode. When recharging, the ions move the other way: from the cathode, through the electrolytes, and onto the anode. The electrolyte separates the anode and the cathode, which effectively separates the ions from moving from one part to the other.

The use of a metal film electrolyte minimizes the danger of an exploding battery. It also helps simplify the manufacturing process. Since Sakti3 was founded, Dr. Sastry and her team have been trying to improve the process necessary to deposit thin metal film electrolytes and scaling for mass production.

Sakti3 has been backed with investments from various major venture capitalists and companies like Khosla Ventures, Bering LLC, GM Ventures and Dyson. Dyson had initially put in $15 million in 2015. He later bought out all the other investors and offered the employees jobs with the company. Sastry has been retained as President.

Even without the electric car unit, the new batteries would be much used in Dyson home appliances. However, Dyson has committed a substantial amount of money to the EV project. Dyson has committed £1 billion ($1.3 billion) in the EV project, and an equal amount in the battery unit. Unlike Tesla, the Dyson EV will not be sports vehicles, but premium family cars. The target is to put the EV on the road by 2020. Dyson bought a former RAF WWII airbase in Wiltshire where the car company is now located.

There is an invention that can replace coal powered plants in generating energy. It is renewable, passive, could potentially generate more than 325 gigawatts of electricity, but might cause a change in local climate.

The technology, however, does not exist yet; it is a bold idea that scientists and researchers are exploring at length. It’s called an “evaporation-driven engine” and makes use of bacterial spores to generate energy.

The spores are on the surface of water, like lakes and water reservoirs, and are connected to a tiny power plant. Movement from the spores’ expansion and contraction due to the absorption and release of air moisture drives tiny engines, which then convert the movement to electrical energy. It has been estimated that an 8 cm x 8 cm (3.15” x 3.15”) of water surface with a tiny evaporation engine can generate 2 microwatts (µW) of electricity, with a burst of up to 60 µW.

The key takeaway is that after doing the math, it is found would take a big surface area to generate a sizable amount of energy. On the plus side, it is not dependent on the sun nor wind, and the energy produced does not fluctuate. Since there is no intermittency of power generation, there is no need for batteries to store energy for off-peak hours. Another upside is that the spores decrease the evaporation rate, which would increase the surface water temperature. This increase can further add to the energy being generated by the evaporation engine.

While the energy produced is relatively small, it can scale up given enough surface area. This is where some concerns would come in. With an evaporation engine power plant covering a large lake, the ecosystem could be changed both by the surface devices, as well as the rise in temperature. In addition, it will also change the aesthetics of the place.

Dam reservoirs would be ideal locations for these power plants, as most dams have significant surface areas. The plant can also share distribution and transmission networks with the dam.

The engineering and the design of the actual device has yet to be created. In order to be viable, it has to generate more energy, and the fabrication of the equipment has to be as cheap enough to be economically feasible.

Looking Deeper at the Potential of Evaporation Engines

A research team from Columbia University created the study on the evaporation engine, and published it in Nature Communications, a peer-reviewed scientific journal. It was co-authored by Dr. Ozgur Sahin, an associate professor of biological sciences and physics at Columbia University. The team from Columbia was also able to power a small car with the use of the bacterial spores and the evaporation engine. Prior literature was from the Massachusetts Institute of Technology (MIT) Technology Review which computed the output of these power plants.

One other advantage of these evaporation engines is that they can continue to generate power even after the spores die. Since the individual units are small, they can also be easily setup as long as there is a way to transmit the power.

In regard to the nature of the power plants, it would take a lot of water surface area to totally replace coal-powered plants. However, even small plants, or a small number of evaporation plants, can go a long way towards renewable energy independence. Once the technology for this bold idea can be developed and refined, it should provide better economies of scale and improved actual production levels.