HELIOVIS has developed and patented a technology that will significantly reduce the cost of solar electricity. Dubbed the "HELIOtube", this inflatable solar concentration system is made completely from plastic foil. Because it replaces heavy metal mirrors and structures with lighter and less expensive materials, the HELIOtube costs up to 3 times less than conventional concentration systems. The HELIOtube is designed for both concentrated photovoltaics (CPV) and thermal concentrated solar power (CSP).
Solar energy has by far the largest potential of all available energy sources: The radiation hitting the earth is equivalent to 10,000 times the world energy consumption. The main challenge for using it on a large scale is the high investment cost of about 4 million € per MW of installed capacity. In addition, solar energy production is limited by the duration of sunshine and lies between 1,000 and 2,500 MWh per year per installed MW, depending on location and the type of installation. This compares to 3,000 or more MWh for hydroelectric, thermal or nuclear power plants. As a result, the average production cost[1] for solar electricity lies between 0.15€ and 0.40€ per kWh[2].
The goal is to reach “grid parity”. For individual customers this means the cost of solar electricity has to fall below the price they are paying for energy. As soon as this happens, they are better off putting solar panels on their roofs than buying electricity from the grid. In some regions of Italy and the USA this is already the case due to the relatively high irradiation and electricity prices of over 0.20€. However, the more important threshold is the wholesale market price, which is currently below 0.10€ per kWh. Only if solar electricity falls below this limit will it be more profitable to build solar power plants than conventional ones.
The two major technologies for solar power generation are photovoltaics (PV) and concentrated photovoltaics (CPV) on the one hand, and thermal concentrated solar power (CSP) on the other hand. PV/CPV refers to the direct conversion of sunlight into electricity with solar cells. CSP means that sunlight is concentrated to generate heat, which is then used to power a turbine that produces electricity. CSP is slightly cheaper than PV/CPV. Even so, a dramatic cost reduction is required for both technologies to achieve grid parity. HELIOVIS has developed and patented a new approach that promises to make this possible for both CPV and CSP.
Conventional concentrated photovoltaic systems (CPV) replace solar cells with a shaped mirror or a lens that focuses sunlight onto a solar cell 50-500 times smaller than the aperture of the concentrator. The solar radiation hitting 1 square meter of surface is thus transformed into electricity by a solar panel measuring only 0.002-0.02 square meter. With the mirror costing about EUR 30.- per square meter or 90% less than solar cells, the savings are enormous, even taking into account the additional cost of cooling the solar panel and for the required tracking mechanism.
The twin technology of this “concentrated photovoltaics” approach is called “thermal concentrated solar power” (CSP). It uses the concentrated sunlight to heat a fluid (oil or steam) in a thermal receiver pipe. The heated fluid is then used to generate electricity with turbines. By storing the hot fluid, CSP allows solar energy to be buffered overnight and produce electricity 24 hours a day.