In a recent webinar Bob Magyar, a senior business development executive for VARTA Storage Group, presented on the state of battery storage in the U.S. today. Here’s a recap of his presentation, including discussion on who may benefit from battery storage, important regulations to follow and tips for battery sizing. You can watch the full webinar here.
Battery storage covers a large area, from 1-kW systems through 70-MW storage facilities. Magyar described the basic homeowner system as having inverter-based battery storage that feeds from the electrical grid through the main AC panel to the inverter, which then charges the batteries. The feed may also be taken from an AC generator. In the PV-solar industry, the solar inverter feeds the flow of electricity to the batteries.
Who can benefit from battery storage?
- Small business owners: storage can resolve business disruptions when power is lost
- People on medical assist devices (non-critical) who typically do not own generators
- People who cannot or will not use generator due to safety concerns and property restrictions
- Commercial accounts: storage can reduce demand charges
- Areas vulnerable to extreme weather conditions (such as shore and resort properties)
- People who own seasonal or second homes
Changes over time
As many solar industry veterans may know, the battery storage business once consisted solely of non-integrated pieces and parts. “It was tough,” Magyar noted. “You have one company’s batteries, another company’s inverter and charge controller, monitoring from yet another company and then building enclosures, building proper ventilation and so on.”
Then, semi-integrated models began to emerge: factory-made enclosures for the batteries, and “smart heads” with the inverter and the charge controller adjacent to each other, for example.
In the last half of 2012, fully-integrated systems took it one step further. “High-quality cabinets came out, sized and designed to handle the inverters, the batteries and the battery loading,” Magyar explained. “Good things started to come from this approach, including one manufacturer’s warranty for all the component parts.” Fully-integrated battery storage systems were easier to handle and maneuver. Monitoring and communication also improved.
Battery storage versus generators
Magyar went on to speak about the advantages of battery storage systems over generators. “Battery storage systems will eliminate carbon emissions,” he said. “Carbon monoxide poisoning, also tends to be a risk of generators that are improperly used.” Noise, fuel and the possibility of theft are eliminated with battery storage systems.
Battery storage is becoming more popular as it’s increasingly seen as having “multi-faceted value.” Magyar explained that it has “less moving parts,” meaning lower service time and costs. Storage systems can be sited indoors because they don’t have the same emissions issues as generators. This also means they are not subject to outside weather, removing the need to clear snow and ice buildup, as required with generator units.
Business models of today and tomorrow
Today’s business case models for battery storage include both emergency backup and off-grid power, as well as commercial accounts for demand response. “Emergency backup power is fairly uniform across the country; more acute in the Midwest and becoming more acute in the Northeast,” according to Magyar. The off-grid market lies beyond the utility grid, meaning home or property owners in those areas have to provide their own power. As far as commercial accounts go, Magyar explained “There are a number of demand-response programs where the utilities will pay incentives for commercial accounts to leave the electric grid during periods of high demand because of the cost of fuel.”
Proposed models of the future include self-consumption, energy arbitrage and interactive microgrids. Self-consumption with a PV system sends power to the batteries during the day, which can then be used at night, all while still connected to the grid. Magyar noted that utilities are resistant to the concept in the United States, but changes are starting to advance in select parts of the country. The next model, energy arbitrage, consists of buying power during the utility’s cheapest kilowatt hour, and then using it during the high time. Magyar said this is a common strategy in the western United States. Lastly, in the interactive microgrids model, an area would completely take itself off the grid through a combination of solar, heat, battery storage and strong energy efficiency measures. Magyar noted that all three of these future business models would most likely only be used with backup power or off grid power with generators.
Battery storage regulatory landscape
Battery system storage currently falls under NFPA 70 of the National Electric Code (NEC) regarding energy storage systems. NEC has definitions in the code for what is and what is not battery storage. With these rules in mind, Magyar recommended using UL-certified or ETL-certified equipment. The rules are specific and may seem complex to some, however, Magyar gave examples of unsafe battery conditions (pictured) to illustrate the safety concerns Code 70 is taking into consideration. “This is more of a uniformed approach,” he said.
“The key to reading the National Electric Code in section 608 is to know and understand what type of battery storage system that you’re representing or considering buying for your customer,” Magyar said. “To provide a good installation, an installer should understand what type of battery the manufacturer is presenting and how it inter-reacts with the NEC stipulations.”
Importance of proper battery sizing
One of the advantages of generators is simple: you put fuel in it and it’s going to run. “Obviously even then you need to know total wattage, but setting the customer expectation of knowing what they have and what their future wattage will be is simplified by the many online calculators and descriptions of the amount of wattage that varying appliances pull,” Magyar said.
However, if you’re selling and representing battery storage systems, sizing needs to be more targeted: Again, a lot of online software is available. Sellers and installers may use online software for calculating the specific load and use of a system on potential backup. Calculating battery banks, the type of battery, the temperature and depth of discharge is also possible online. “One can always check individual sources, but for the most part, the online calculators are fairly accurate, and they’re good to incorporate in sizing-out systems,” Magyar recommended.