Reliable Renewables Provide Peace of Mind!
Batteries power our phones and cars. Why shouldn’t they power our homes? Well, until recently, batteries for home energy storage didn’t last long enough for this application, so it was much cheaper to transport power than store it. Two key factors have helped to change that:
- The Cost of Producing and Delivering Electricity to the Energy Grid Won’t Stop Rising
- The Length and Strength of the Best Battery Technologies Have Steadily Improved
With weather events that damage old electrical equipment occurring more frequently, and utility companies raising rates year after year without providing better service, energy independence starts to sound like a more appealing idea!
The next big movement in clean energy is the Energy Storage System. These are batteries placed in or outside of your home to power your everyday energy needs. They can be used to store solar energy for demand management, peak times of use, or as an emergency backup.
As the world moves closer towards 100% renewables, Energy Storage Systems will become central to the picture in a big way. The biggest opponents of renewable power say 100% just isn’t possible when renewable power isn’t consistent; when the sun has to set until tomorrow. Energy Storage allows us to mitigate this and create an even greater sense of energy independence. Now we can power the world and protect our homes from power grid emergencies!
Residential Battery Systems are more affordable than ever!
Prices for lithium ion batteries have fallen 85% since 2010, with projections stating a further fall of 65% by 2030. NYSERDA, New York State’s Energy Research and Development Authority has even released a grant for Energy Storage Systems in Long Island, with other utilities set to follow suit shortly. So whether you’re an existing solar customer, or someone considering the switch, Solanta’s expert consultants can walk you through how energy storage will integrate with your home.
Energy Storage Technology
There are a number of battery technologies that are constantly in development, but the the two that have been used in most installation to date are Lead Acid and Lithium Ion. These are technologies that have been researched and developed over several decades by a number of different manufacturers, and so there is a lot more historical testing data. Lead Acid batteries have been in use for cars and remote and off-grid systems for years, but the rise of mobile phones and mobile computing devices over the last two decades has lead to a wave of research into Lithium Ion and other more power dense battery technologies.
Lead Acid batteries date back to the 1850s and are still the most common type in use worldwide. Their many home storage applications have resulted in years of research and development that has naturally pushed the technology ahead. While Lead Acid batteries are known for their long shelf life, their depth of discharge is very low. If they are discharged more than 50% before a recharge, they can experience significantly reduced cycle life: as low as 200 to 300 battery cycles. These batteries can last over 20 years in off-grid settings when not in constant use.
SimpliPhi and Outback are two of the most popular manufacturers of Lead Acid battery systems because of their experience and product lines. They have both AC and DC configuration options with built in Battery Management Systems (BMS) and modular battery packs. Since the individual battery modules of these systems can be replaced if one fails, it also allows for the system to be upgraded as your storage needs grow.
Lithium Ion batteries are an increasingly cheap form of home energy storage. Through years of innovation, manufacturers like LG, Enphase, and Tesla have managed to build Energy Storage Systems with 100% depth of discharge, 96% round trip efficiency for AC to DC inversion, and 10 year warranties! They must be installed indoors or in a sealed NEMA 4 rated container if outdoors. Jurisdictions like New York City are still hesitant to allow this type of technology indoors due to the volatility, as Lithium reacts with water to make fires worse.
LG, one of the most trusted names in solar modules, produces both DC and AC coupled models of their home energy storage system for integration with new and existing systems. Enphase only makes an AC system that pairs well with their micro inverters, but is more modular as it comes in a small 1.2 kWh size, meaning units can be added in the future as energy needs changes over time. Tesla and Sonnen also make AC coupled systems with fine grain power management controls, and incredible warranties.
Researchers and manufacturers are constantly searching for a new battery technology that can provide the long-term performance, power density, and low enough prices to reach a mass market like Lead Acid and Lithium Ion have. So far, they have only been able to meet one or two of these goals at a time, but there are some promising developments in recent years, especially from Vanadium Flow batteries.
A vanadium flow battery consists of two power cells filled with electrolytes that are separated by a thin membrane to prevent them from mixing. In vanadium flow batteries, both cells are connected to storage tanks and pumps so that very large volumes of the electrolytes can be circulated through each cell. This circulation of liquid electrolytes is somewhat cumbersome and does restrict the use of vanadium flow batteries in mobile applications, effectively confining them to large fixed installations. This is part of the reason research into this technology has been markedly slower. While some vanadium flow batteries for home storage use have been developed, they are not yet cost effective or widely available, but they do offer high power density.
Solar Plus Home Energy Storage Integration
Home energy storage systems can be built with new solar installations, or integrated with existing installations using an AC to DC inverter. These systems will store any excess power generated by solar that is not being used, so that leftover clean energy can be utilized when peak demand is high and utility rates rise, or as a backup in emergencies when the utility grid is down. We may need to upgrade your old energy monitor, but after install, Solar and Energy Storage can usually be monitored together in one application.
There are two different type of Energy Storage Systems: one is a powerful DC coupled system that takes power directly from a new solar installation before it is inverted to AC power, and then there are AC coupled systems, which work with a DC to AC inverter as an add-on to existing solar systems, especially those that have micro inverters on the rooftop. Both can smartly switch from charging to discharging to protect you from high grid prices and disconnect from the grid in a blackouts.
Local Regulations Are Still Shifting
Solanta often operates in areas that have strict regulations regarding the installation of home energy storage systems. We do our best to work with the local municipalities and many are becoming more friendly to energy storage systems each year. For instance, New York City is still very concerned with the flammability of lithium ion systems, and we are too. We are all working together to solve for this issue with safer solutions that can eliminate the concerns.