Solar power technologies have evolved over the past years, addressing some of the top concerns faced by providers. However, there are factors that remain out of an operator’s control – for example, the amount of sunshine and power demand.
For example, while solar plants “go to sleep” after the sun sets, connected transformers still consume electricity. This small loss — a couple of kilowatts each night — can add up to big costs — up to as much as $800,000.
On the other hand, switching transformers off can cause voltage spikes, deteriorating the insulation material over time. It also produces large current inrush when reconnecting to the grid, which can be six times higher than normal transformer operation. All this adds extra mechanical stress to the equipment, shortening its life cycle. That is why many operators have, in the past, chosen instead to leave it on and allow electricity to slip away each night.
GE has developed a solution that can help reduce some of those incremental costs being incurred. In the course of switching the transformer on or off, inverters provide reactive power to magnetize the transformer. Once the voltage is synchronized with grid level — meaning voltage levels on both sides are equal — transformers can then be connected or disconnected smoothly and cleanly. By operating in such a controlled way, stress on the system is minimized, which should help equipment achieve a longer lifespan.
In short, the intelligent controls developed by GE simply disconnect transformers automatically at night, no-load losses are eliminated and significant savings can be achieved, GE said
Further cost savings can be made by wrapping the equipment into a container. How? A container can be used both as a skid and enclosure, providing both the base for the equipment and its protection. The container itself can be shipped, therefore reducing transportation costs.
The pre-assembled and pretested solar container requires minimal field work during installation on-site, which greatly reduces risk and time needed during commissioning. Every piece of equipment is already set up inside the container, meaning just the cables need to be connected and the power switched on. Moreover, as transformers are premagnetized and synchronized, it allows multiple systems to be connected to the grid simultaneously, further accelerating field commissioning.
The same principle can be applied in the event of an outage. As the entire solar plant can be connected to the grid all at once, it achieves a faster recovery.
Further GE has also developed a new Silicon Carbide (SiC) to help gain power conversion efficiency up to 99 percent EU level. Read here.
By using technology and innovation to reduce daytime and nighttime losses as well as to accelerate commissioning time, solar farm operators can begin to cut down their list of worries and focus on what’s important, GE claims.
Designed specifically for utility-scale solar farms, GE’s Power Conversion business’ LV5+ eHouse solution coupled with SiC technology is ready to help operators make the most of what they can control and gain higher energy output over the lifetime of the power plant.