Why Microgrids Are the New Power Generation Solution for Remote Locations
byDjohnston09-15-201611:24 AM - edited 09-15-201611:27 AM
For years, microgrids have been a solution for powering remote locations without easy access to a larger, more reliable power grid. A microgrid is a group of interconnected loads and distributed generation sources that act as a single controllable entity used to power locations such as mine sites, telecommunication towers, remote villages, resorts and small islands. While the microgrid concept is not new, more efficient technologies and the declining costs of renewable energy solutions make microgrids a more viable option for power generation today.
Improved Microgrid Design
Traditionally, microgrids have relied solely on engine- or turbine-driven generator sets to produce power. While reliable, this method of powering microgrids can be expensive in the long run and is dependent on fossil fuels.
Today’s microgrids combine the latest renewable energy solutions, energy storage and controls technologies with traditional generator sets. Thanks to a recent rapid reduction in technology cost, today’s microgrids can be more cost-effective compared to traditional power generation methods in remote locations. These new microgrids harness the low-cost and fuel-free benefits of renewables while offsetting their intermittency with the reliability of generator sets and energy storage solutions. A sophisticated control system ties all of the components together, producing a dependable, clean and affordable way to generate power.
Energy storage can perform several functions in a remote microgrid. First, it provides an instantaneously dispatchable power source to stabilize the rapid fluctuations in power output typical in solar-and wind-dependent systems. This function enables the system master controller to shut down all generator sets when average renewable output meets the load, enabling maximum fuel and generator maintenance cost savings. Second, energy storage can provide a “time-shifting” function, where excess energy from the solar panel or wind turbine can be captured, stored and supplied back into the load at a later time. This extends the generator shut-down period well past sundown or a change in the weather, further increasing fuel and generator set maintenance cost savings. Depending upon the application specifics, renewables and energy storage can even be sized to cover 100% of the load while minimizing or eliminating generator set operation.
Rechargeable metal-air energy storage is an advanced energy storage technology that promises low-cost and long-life. This safe, non-toxic technology uses zinc to store energy. Zinc-air storage lasts twice as long as traditional lead-acid batteries and has fewer environmental concerns.
Additionally, the zinc-air storage helps to reduce theft, a common problem in remote telecommunications applications. The zinc-air storage requires the proper electronics package to function, and the materials used have little residual or retail value, meaning the zinc-air cells typically cannot be stolen and sold for a profit.
Through energy storage technology, the microgrid is able to tap into the energy saved in the batteries before turning to the diesel-fueled generator sets. This provides an extra layer of support, reducing generator set runtime and helping to prevent power outages.
Diesel Generator Sets and Hybrid Microgrids
While renewable energy costs are declining and energy storage helps alleviate some of the dependency on generator sets, traditional power generation is still an integral component of today’s microgrids. There will be times – and site locations – where the conditions are not ideal for generating power from renewable sources, and energy storage does not have the capacity to power the load. In these situations, traditional generator sets are still the best choice. In a remote location, reliable power from a microgrid is crucial. By integrating the long-proven dependability of generator sets with alternative power sources, today’s microgrids are securely backed up and prepared for any situation that might jeopardize power generation.
Long-Term Benefits of Microgrids
Considering the use of renewable energy sources, traditional power generation and energy storage, the benefits of microgrids include:
Life-cycle costs of microgrids incorporating renewable energy sources can be lower than standalone diesel solutions, reducing total owning operating costs
Renewable energy capacity can account for any percentage of the energy consumed, reducing dependence on costly fossil fuels and lowering emissions
Microgrids have superior stability with multiple points of redundancy throughout the system
Advanced energy storage solutions are integrated into system
Cat® Microgrid Technology
Launched in May 2016, Cat Microgrid technologies can be purchased as turnkey installations or design-to-order solutions through the global Cat Dealer Network. Ranging from 10 kW to 100 MW, units can be added in a modular fashion to create systems customized for a variety of power needs and can include any combination of the following elements:
Thin-film solar modules, which capture more energy, especially in high-temperature, high-humidity, desert and coastal climates
Energy storage including ultracapacitors, lithium-ion and rechargeable metal-air technologies that provide the most economical and advanced energy storage with controls and monitoring down to the cell level
Cat generator sets powered by diesel, heavy fuel oil (HFO), natural gas, biogas or dual fuel, offering high power density, high-part load efficiencies and excellent capability to follow loads
The Cat Microgrid Master Controller to monitor and optimize power usage in the microgrid
In remote areas, access to reliable, affordable power is challenging. With microgrids, communities and industries can receive the vital power they need. Today’s microgrids combine all of the strengths of traditional microgrids with the added benefits of environmentally friendly power sources and increased dependability. With solar power and wind power costs declining, microgrids with renewable energy sources are the most effective way to produce clean, reliable and affordable power. Now is the time to recognize microgrids as an alternative to conventional power generation. To learn more about microgrids, please visit www.cat.com/microgrid.