As at 2014, the cumulative global capacity for solar power has reached 178GW. But, this number pales in significance when we consider the net energy consumption by the world’s population. Among the major industrialised nations, in 2016, Germany is leading the way and on 16th May 2016, the government met nearly all its energy demand of 45.8 GW from renewable energy, for the first time. Germany also understands that there should always be a source of backup power in the form of thermal energy and thankfully, the nation can export her surplus power. Most regions of Germany receive an average of about 1500 hours sunshine annually, barring some pockets in Southern Germany where it edges up closer to the 2,000 hours mark per annum. Interestingly, Australia receives more than 3,000 hours of sunlight every year but lags behind in solar power production and consumption. Australia generates about 5GW of solar power representing 9% of the total energy production/consumption. Setting up a solar panel is a good idea for power consumption. You can set up systems across all types of buildings including businesses, schools, and homes. You can go through the case study of Euro Solar to know more about the solar panels and energy consumption.
The Road Ahead
With more and more nations focusing on clean energy and the world as a community getting more concerned about climate change and its potentially devastating effect on the human race, solar energy is bound to be harnessed at an increasing pace with more GW being added every month. The following five technologies are expected to lead the way to make this global energy revolution happen. Two major constraints that impede the progress of solar panel industry and therefore solar generation are – the cost of solar PV panels which is stiff presently, with a projected payback period put at about 19 years. This needs to moderate to below 10 years to make the upfront investment more viable. The second constraint is storing energy produced. In some regions where sunlight is abundant, all the energy produced in a day may not be consumed by those who own the installation. Commercial installations will have to find ways of storing solar energy efficiently and distribute them via the grid. That brings into focus, the means for storing solar energy.
Lithium-ion batteries are already gaining popularity, and One of the American Manufacturer have already launched their Power pack and Power wall, with supporting infrastructure. But the offering is in its nascent state, and the pricing, at first sight, is not ideal for mass consumption. As the popularity of solar power storage and utilisation picks up, the product is expected to achieve better economies of scale leading to significant reduction in prices. Other major electronic manufacturers have already recognised the opportunities in Lithium-ion batteries and are building large capacities of batteries around the world. With more consumers willing to put their money behind solar storage systems, there will be more players entering the segment contributing to healthy competition and affordable pricing.
Lithium-ion batteries are known to be useful only for small-scale power consumers such as computers and smart phones. When it comes to large-scale use, we need a different system. This is why companies have been focusing on flow batteries. This type of battery converts electric energy to chemical energy and back to electrical energy. The chemical is capable of being stored in vast volumes for later use and power thus stored can be significantly higher compared to lithium-ion batteries.
Flow batteries are similar to rechargeable batteries in a remote, except that it is on a larger scale. Flow batteries are still being developed and much more research is needed before they become commercially viable. But the technology holds great promise for the future.
More companies now invested in High view Power Storage, which uses liquid air for storing energy. By cooling air to 196 degrees Celsius, the air is turned into liquid. 700 litres of cooled air can be kept in the space taken up by just one litre of hot air. Further, the storage of cooled air needs only insulated tanks (stainless steel). To generate electricity, the cold air is warmed up to expand and power a turbine which in turn produces electricity. This technology may come in handy for storing large volumes of energy but not as a fast source of energy.
Theoretically, hydrogen is the best medium to store energy. It is benign even when it leaks and available in abundance. Turning water into hydrogen and then hydrogen to electricity is relatively straightforward and commercially viable.
However, hydrogen is neither efficient nor cost effective. But, over the longer term, hydrogen has the potential to stand neck to neck with solar energy. A project recently completed by ITM power involved converting the wind to hydrogen for energy storage and fueling vehicles. This technology can potentially apply to solar energy. Theoretically, projects of a similar nature can store hydrogen for several months and even move it around a country. But, how soon this becomes a reality cannot be predicted.
This is perhaps the easiest way to channelize solar energy to the electricity grid almost seamlessly. Presently this is just a small component in any electricity network today. Customers can reduce their demand when solar plants do not produce energy and conversely increase demand when the plants are producing energy. Demand response can work on large solar plants as well as small systems on rooftops.
Energy Storage – A Major Hurdle
Energy storage is one major hurdle in the growth of solar energy because of the manner in which solar energy is generated. Some calculations indicate that it takes about 115,000 square miles or the area of Arizona to produce all the energy needed by the world today. But, building such a massive solar power generating unit would call for an investment of trillions of dollars, but mostly cannot be ruled out. When that happens, storage of energy will come to the forefront and the technologies discussed above will invariably come alive.
If the energy landscape can change in the next two decades, the human race will be a lot happier. But, for those involved in traditional means of generating energy, that could be bad news.
- Wald, Matthew, L. Wind Drives Growing Use of Batteries, The New York Times, July 28, 2010.
- Erik Ingebretsen; Tor Haakon Glimsdal Johansen (July 16, 2013). “The Potential of Pumped Hydro Storage in Norway (abstract)” (PDF).
- Norway: Energy storage for Europe (video report), Deutsche Welle, July 7, 2014.
- Wald, Matthew L. Ice or Molten Salt, Not Batteries, to Store Energy, The New York Times website.