Electrical power generation across the world must overcome a significant challenge: using renewable energy sources to reduce greenhouse gas emissions. Although renewable energy sources have been around for a while, there is still difficulty in finding a more efficient and cost-effective way of storing harvested energy.

Take the solar panel issue that happened in Hawaii. They had clear skies and high winds during the daytime that yielded an overproduction of renewable electrical energy. The overproduction of renewable electrical energy could not be fed back to the grid, since it could jeopardize the grids safe operation. Calm nights produced no renewable electrical energy and forced electrical power to be generated from traditional sources.

Customers with renewable energy could not benefit from zero net billing, and customers still had to pay half of the electric bill on top of the loan payments for the solar panels and wind farms. With this additional cost, the renewable energy strategy ran in the red. It is highly recommended that companies and individuals invest in renewable energy storage systems to fix these problems and store the surplus energy which will enable true zero net billing.

There is a wide variety of electrical energy storage technologies from mechanical, thermal to chemical, thermochemical, electrochemical and electrical. All of these electrical storage technologies struggle to isolate and transform the harnessed power efficiently.

Because of this movement to harness power, lithium-ion batteries have become the leading renewable energy storage technology. They allow a high amount of energy to be stored with a low self-discharge and almost no memory effect.

This article will highlight the key aspects of power conversion and battery management systems involved in electrical energy storage of renewable energy sources.

High Voltage Energy Storage for Renewable Energy Sources

battery-management-renewable-storageThe intermittent nature of renewable energy sources make power grids unstable. However, electrical energy storage systems smooth the output delivering a stable power source. The renewable energy storage system is designed to charge during peak wind and solar times and discharge during off-peak times to increase the efficiency of the generating system.

Typical solar photovoltaic systems use electrical energy storage systems that operate in a range from 600 to 1,500 volts of direct current. Arrays of lithium-ion battery cells must be connected in series to support high voltage systems.

The main advantage of high voltage storage systems is that the energy is already coherent with the voltages of renewable energy sources and grids. This minimizes power conversion losses.

The utility grid operates at high voltages to transmit energy at low current, which in turn yields lower resistive loss. Conversely, renewable energy sources aim to work at mid-range voltages and currents, and still minimize losses while simplifying the overall power conversion system.

Given the advances in lithium-ion battery technologies, mid-range voltage storage arrays will reduce cost in the renewable energy storage systems. This price reduction results in simpler inverters with fewer components at a higher voltage and insulation rating. Higher voltage battery cells allow lower current for the same power rating. This further reduces the wire size and cost, however special attention needs to be put into getting the right voltage isolation levels.

Some battery systems, often used in telecommunications and medical applications, need to withstand high power transients. These systems require even higher voltage isolation components to withstand the transient voltage.

Control and Power Isolation in Renewable Energy Systems

bms-PH9185-PH9400-high-isolation-transformersWind, solar, and stored electrical power eventually needs to be converted by a DC to AC inverter to be used in the home or factory. The inverter generates AC by switching on and off circuits typically through IGBTs or MOSFETS.

The high voltage isolation between the control circuit and the IGBTs or MOSFETS is accomplished by high voltage isolation gate drive transformers such as the Pulse Electronics PH9185 EP7 series High Isolation SMT Transformer, or PH9400 series “Sidecar” High Isolation SMT Transformer.

Unlocking the Power of Renewable Energy Sources Through Electrical Energy Storage

Trends indicate the cost of renewable energy is expected to keep dropping as demand and production increases. Harvesting renewable energy is a better alternative to power the world, not only from an economic perspective, but from a health and climate perspective as well.

Electrical energy storage is crucial to unlocking the benefits of renewable energy and enabling its integration to existing grids. The success of clean energy relies on technological improvement and lower cost of its power conversion and storage. It will only be achieved by utilizing technology from reliable and established sources.

Storage and distribution technologies that boost the use of renewable energy sources over fossil fuels are essential for developing more efficient power conversion. High voltage is widely adopted as a strategy to minimize energy losses. The use of high voltage renewable energy storage systems will create better-engineered power electronic devices that provide proper control and power isolation to higher potential energy solutions. Likewise, electrical storage solutions, such as lithium-ion batteries, require reliable battery management systems to monitor and ensure energy is being stored safely and efficiently.

To unleash the benefits of renewables, tailor your power conversion and battery management systems. By tailoring your solutions, your power and isolation levels will be cost-efficient and a reliable electrical energy source.

To inquire about how the experienced team at Pulse Electronics Power BU can assist with your Battery Management System project, including lead times, competitive pricing, samples and more, simply contact product support or use our quote form by clicking the button below.