What’s New in Solar Energy Research in 2018
Source：Forbes
From：Taiwan Trade Center, Los Angeles
Update Time：2018/07/17
Solar energy is one of the most diverse forms of energy on the planet and it can be used for a variety of things. This includes but not limited to electrical power, heating and cooling, water heating, industrial process heat, cooking, transportation, fuel production and even environmental clean-up. We receive it directly as radiation which carries no mass with it and is of the highest power. From direct sunlight or radiation, we are able to convert it to many other forms for our everyday use. (for details please see Chapter 1 of Principles of Solar Engineering, 3rd Ed. By D. Yogi Goswami, CRC Press).
Sunlight however is not perfect, as it is only available during the day time where the sky is clear with no obstruction from the rain or clouds. We also get indirect forms of solar energy through channels such as wind, biomass, ocean energy, hydro…etc. Fossil fuel is also an accumulated form of solar energy, which has been consumed and depleted.
Thus, research continues to look into these three goals for the future.
1. Increase the efficiency of conversion to other forms while reducing the current cost.
2. Store energy more efficiently to reduce the costs.
3. Find new ways to convert solar energy to useful forms.
Since electricity has established itself as the default and preferred form of energy for almost all of our needs, a major push has been made to increase the efficiency on the conversion of electricity and cost reduction. There are two main methods for converting solar energy to electricity – photovoltaics (PV) and solar thermal power (commonly known as CSP, which stands for concentrate solar power).
The present trend in researching on PV, it is focused on using earth elements including: Cadmium, Tellurium, Gallium, indium, selenium…etc. Silicon is still the main material used in making solar panels; however, it is not quite resourceful.
Since the cost of PV in the last 10 years have continued to drop, CSP sales have not been so competitive. In general, CSP has two big advantages over PV:
1. It uses the same thermal power conversion as the conventional thermal power (fossil fuel or nuclear based) and can be integrated with existing power infra-structure easily.
2. It uses thermal energy storage which is about one tenth of the cost from battery storage.
The essential part of complete use of solar energy is its savable nature of sunlight that is stored and available for later use. There are many ways of storing solar energy, including batteries, thermal energy storage, pumped hydro, compressed air…etc. The primary objective is to increase the amount of energy stored to batteries. Thermal energy storage (TES) is by far the cheapest way. The trend in electrochemical energy storage is the potential increase in Supercapacitor storage. Supercapacitors can deliver rapid discharges with low storage capacity. Research is carried out for increasing Supercapacitor energy density, aiming to bring it close to the battery energy density. Another research on storing solar energy is by using it to generate hydrogen from water. Hydrogen could later be used in producing electricity in a fuel cell.