The following are principal components of the Stone Edge Farm MicroGrid. For a generic list of electrical terms and devices, please see our Glossary.
Aquion Energy aqueous hybrid ion battery
Also known as a sodium ion battery, this 28kW/380kWh storage device connects two strings of seven LM100 48V battery modules in series that are combined in one 672V string by the Ideal Power power conversion system (see below). The battery’s unique chemistry combines abundant, non-toxic materials: an alkali-ion saltwater electrolyte, manganese oxide cathode, carbon titanium phosphate composite anode, and synthetic cotton separator. It is non-flammable, non-explosive, and truly sustainable.
Capstone C65 microturbine.
This 65kW natural gas-fired variable external combustion engine operates at 90,000 rpm with peak efficiency at 80% (51-52kw), producing electricity at a cost of five to seven cents per kilowatt. Essentially a stationary jet engine, it has one moving part and runs on two foil-air bearings, more quietly with increased speed. Exhaust temperature can reach 588° F. It operates on a 480V/3P service and does produce a small amount of carbon dioxide; we hope to power the microtubine with hydrogen by 2018, working in conjunction with the University of California, Irvine Power Laboratory.
Emerson ASCO 7000, 300 series automatic transfer switches.
These switches connect the MicroGrid to or isolate it from the utility grid. When the switches separate, they create a physical opening, an air space. If the utility grid fails and the MicroGrid is already producing power, the ATSs can automatically route power onto the grid.
Energy Storage Systems iron flow cell battery.
This 10kW/65kWh iron flow battery is non-toxic with an iron and saltwater electrolyte, patented pH stabilization to ensure a long life of over 20,000 cycles and >70% peak round-trip efficiency. Two 500-gallon tanks hold the electrolyte fluid that is phosphorescent green when charged and rusty brown when discharged. The 480V/3P battery electroplates (deposits iron) on the negative side to charge, and deplates on the positive side to discharge (returning iron into the tank). Environmentally safe and recyclable, it has no hazardous materials, is not flammable or corrosive, and has no noxious fumes.
Enphase Energy M250, S280 microinverters.
The M250 microinverters are deployed one for each solar panel for improved efficiency and cost-effectiveness. The S280 version is paired with fuel cells. Both are smart grid ready.
Heila IQ optimizer
This optimizer was designed on site at the Stone Edge Farm MicroGrid by one of our interns, Jorge Elizondo. It translates disparate communications from numerous technological devices into a common software language. His version 2.0 has no screen, can be accessed by cell phone and installed by a regular electrician. It connects with and integrates any energy asset. This local control failsafe device is designed to work if the other two control systems are lost or compromised.
Ideal Power grid-resilient 30 kW AC/DC/DC power conversion system
This compact power converter efficiently transfers energy between its one AC and two DC power ports, simplifying integration of solar-generated energy storage, and eliminating an external isolation transformer.
Millennium Reign Energy 330 Triple Twin electrolyzer
The electrolyzer consists of three pairs of alkaline cells operated in pairs (2, 4, or 6) as well as purifiers and low- and high-pressure compressors. Hydrogen gas is created using surplus solar energy or energy from the microturbine to split water into hydrogen and oxygen; up to 12 kg of hydrogen can be produced every 24 hours, enough to fuel one car or two forklifts. If a voltage rise threatens MicroGrid stability, the electrolyzer turns on as programmable load reserve capacity. The electrolyzer initially generates 99.8% pure hydrogen compressed to 125 psi. Oxygen scrubbers and desiccant dryers increase purity to 99.999%, while twin compressors boost pressure to 6,000 psi. The electrolyzer operates on a 240V/1P circuit with a 50A breaker. Bulk storage capacity of hydrogen gas on the farm currently is 500 kg at 250 psi and 225 kg at 3,250 psi, enough to operate our fuel cells for 12 days. Eventually we will store 51,000 kg.
Millenium Reign Energy Series 3 hydrogen storage and fueling station
Hydrogen is stored here in 24 one-kg red carbon fiber and steel tanks at 6,000 psi. At that pressure, the J2600 dispenser will fill half a tank for a 150-mile range in the Toyota Mirai fuel cell cars.
PlugPower ReliOn (GenSure) E-2200 hydrogen fuel cell hives
The fuel cell hives reverse the electrolysis process, transforming the chemical energy freed during the electrochemical reaction of hydrogen and oxygen to electrical energy. The byproduct is water. Each of three hive cabinets contains a stack of four 2.33kW units (total 28 kW) of PEM (polymer electrolyte membrane) fuel cells. If individual modular units fail, they are easily removed and replaced. The kWh capacity is dependent upon the quantity of hydrogen stored.
Redflow zinc bromide ZBM2 flow cell batteries
These two units combined displace energy at a rate of 10kW peak with a capacity of 20kWh. The batteries have a fire retardant electrolyte, no thermal runaway, and do not require active cooling.
SimpliPhi Power Smart-Tech lithium ferro phosphate battery
This battery pack, consisting of seven 3.4kW units, displaces energy at a rate of 23.8 kW, holds 45kWh capacity, lasts up to 10,000 cycles, and operates at 98% round-trip efficiency. Non-toxic and hyper-inert, it is extremely safe and completely recyclable. It has no flammable components (the lithium is tightly bound), no possibility of thermal runaway, and requires no ventilation or cooling. It can be overcharged, crushed or burned, and provides greater energy density with no need for heat mitigation.
Sony lithium iron phosphate batteries
This stack of eight units displaces energy at a rate of 2.4kW and has a 9.6kWh capacity.
Tesla Motors lithium cobalt ion batteries
Our Tesla Powerpack battery was the first unit ever made at Tesla’s Gigafactory in Nevada. This utility-scale battery consists of five 50kW/95kWh cabinet-and-rack units, each containing 16 individual pods of lithium cobalt ion batteries identical to those that power the manufacturer’s cars. The 250kW/475kWh capacity battery, the largest on the farm, can discharge a substantial amount of power in a short period of time. Product life is 5,000 cycles. Liquid thermal control systems inside white containers enhance cooling. When the MicroGrid operates in island mode, the Powerpack can generate its own 60 Hz cycles to serve in a master role.