Tech Glossary

What goes into a renewable energy system?

Wind turbine


WHAT IS IT? The wind turbines that IES uses are built as a tower with a three-blade rotor on top. Villages usually install 4-6 smaller turbines. The towers reach between 18-24 meters (60-78 feet) tall, and the rotating blades have an average diameter of 17 meters (55 feet) across. As the rotor spins, gears connected to an electrical generator convert the kinetic, moving energy into electrical energy, which is sent to the power plant. WHERE IS IT? Wind turbines are installed near a village, away from buildings and air traffic. WHY IS IT IMPORTANT? Wind turbines capture wind energy and convert it into electricity for a very low cost.




Electric Thermal Stove


WHAT IS IT? Electric Thermal Stoves (ETS) are super-insulated metal boxes that contain a heating element, ceramic bricks, a blower, and a control panel. They are about the size of a Toyo Stove, and fits easily in someone’s home. In renewable energy systems like the ones IES designs, ETS units run off of surplus energy produced by wind turbines. This energy is directed to individual home ETS units, and residents can use this energy for heat, which costs about 50% less than using diesel fuel. IES is the statewide distributor for Steffes ETS Units: WHERE IS IT? ETS units can be located in homes and commercial buildings. They are about 24 inches tall, 10 inches deep, and 30-58 inches long. WHY ARE THEY IMPORTANT? ETS units provide renewable energy directly to homes and building, generating heat at about half the cost of diesel.




Battery Energy Storage System


WHAT IS IT? A Battery Energy Storage System (BESS) efficiently stores and integrates renewable-generated power into the local grid. It consists of electrical components and control panels contained in a 7x7x7 foot metal box. This system includes battery storage capacity and a Power Conversion System (PCS), which allows renewable-generated power to “jump start” the rest of the grid in the event of an outage. IES is experienced in installing and supporting remote operations for the Hitachi ABB Powerstore in rural Alaska communities. WHERE IS IT? A BESS is installed outdoors next to a power plant. WHY IS IT IMPORTANT? A BESS has the ability to provide “diesel-off” operations—meaning generators are turned off and the entire community is powered by renewable energy. With wind turbines and a BESS, IES communities see about 50% diesel-off time in the first year, and that number only increases as the system is fine-tuned and expanded.




Solar PV Array


WHAT IS IT? A photovoltaic (PV) solar array is a set of panels made up of specialized cells that produce electricity from sunlight. PV panels come in a variety of shapes and sizes and can be mounted on existing structures or on their own metal racks. IES projects in Alaska most often involve about 200kW of solar power, or 34 2x8 foot panels installed on their own racks over approximately 1.5 acres of land. This unit is similar to what IES uses: WHERE IS IT? PV arrays can be installed almost anywhere that receives consistent sunlight (even in Alaska!). IES installs PV arrays near wind turbines, away from the center of town, where they can be easily integrated into the existing power distribution system. WHY IS IT IMPORTANT? PV arrays provide another sustainable, affordable alternative to diesel fuel, and contribute more diesel-off hours for the community. Solar is often complementary to wind power, as there is more sun during the spring-summer seasons when winds are not as consistent.




Microgrid


WHAT IS IT? A microgrid is a self-sufficient energy system for a community. Many villages in Alaska have microgrids, as they are all individual systems not connected to another system. A microgrid can have multiple power sources, such as diesel generators, wind turbines, and solar arrays. When this is the case, the system is also known as a Hybrid Energy System. WHERE IS IT? A microgrid’s footprint is the same size as the community it serves. WHY IS IT IMPORTANT? In rural areas, a microgrid is often the only source of power. The cost, efficiency, and environmental impact of a microgrid can have a huge impact on quality of life for local residents.




Hybrid Energy System


WHAT IS IT? A hybrid energy system gets its power from multiple sources, such as diesel generators, wind turbines, and solar arrays. Hybrid systems use inverters and other controls to switch between power sources and make sure that there is a steady supply of power to the grid. Turning different power sources on and off is called islanding. WHERE IS IT? A hybrid energy system’s footprint is usually the same size as the community it serves. WHY IS IT IMPORTANT? A hybrid energy system can save residents money, reduce fossil fuel usage, and increase energy independence.




Load Regulator


WHAT IS IT? A load regulator balances energy input and output so there is a steady supply of power to the grid. Also known as a “power sink,” load regulators operate in standby mode until they are needed to absorb excess power, like a surge protector for the entire system. Load regulators are installed in existing diesel power plants. Their cooling systems run cooperatively with those of diesel generators, so they also have the effect of regulating the temperature in the power plant itself: WHERE IS IT? Load regulators are installed in existing diesel power plants. WHY IS IT IMPORTANT? For hybrid systems with more than one power generation source, load regulators are critical to maintain a consistent flow of energy.