In many ways, there isn’t much new in renewable energy. Renewable energy, of course, is new in the sense of what it means. The energy source renews itself and its availability is as such plentiful. Yet, both wind and hydro energy have been captured for hundreds of years, for example, in sailboats, windmills, hydro powered mills, saws and other equipment. Solar was harvested in greenhouses and for heating long before there were photovoltaic panels.
Likewise, for us as an equipment supplier for the power generation and utility market, much of what we do is built on something we’ve done for a long time. We have quite recently completed and launched our new generation solar inverter, The Sun Switch. Yet we already have over 6.5 GW of installed power plant capacity using many of the same building blocks and our core competence.
What’s unique about a solar inverter?
Well, there are differences. Solar in many aspects is simpler, as the power source is already direct current (DC). In wind power and a whole variety of drive applications, you need to rectify alternating current (AC) to DC and then invert it back to AC again. From a controls viewpoint, a solar application has what’s known as maximum power point tracking (MPPT), a rather simple control algorithm used to maximize the power outtake from the solar panel array.
Traditionally, the role of a solar inverter was simply to convert DC current from the solar panels into AC current and then feed it to the grid. In the case of a grid disturbance, the inverter was simply tripped off-line. This is still how most inverters for residential and other relatively small photovoltaic (PV) plants operate.
What’s specific about a utility power plant?
Power plants, utilities and grid operators are in the business of providing a reliable power supply to their customers. Power generation assets connected to the grid typically include a wide portfolio of solar, wind, hydro and various thermal power plants heated by coal, oil, natural gas or nuclear power. All of these sources work together to maintain a reliable power supply. When one of these assets experiences a problem and needs to be taken off-line, it is important that the other shoulder the load and keep on producing.
This is where one of The Switch’s core competences comes into play: With our over 6.5 GW installed capacity, largely in remote areas with a weak power grid, we’ve fine-tuned and successfully field-proven our grid-support capabilities. These functions include low-voltage ride-through, reactive power injection, over-frequency response and ramp-up control, as required by the most stringent and newly established grid codes.
All in all, there are a lot of similarities in the equipment we make for various power plants. The grid support core competence is crucial to achieve the reliability and excellent performance our customers rightfully expect. The difference between a residential installation and a power plant is significantly bigger. Our solar inverters and all we do are utility grade – built to be truly tough.
Benny Nyberg, Key Account Manager/Business Development
