Nova Solar Capital
Grid-Tied AC Coupling Residential Battery-Backup System Test Installation
What are we offering, and why?
A battery backup system is a natural complement to solar PV, but the ability to use a backup system with micro inverters is a fairly recent development, and at Nova Solar capital we want to test one to understand its installation and operating characteristics in a real-world situation.
We will install the backup system with one of the first solar installations purchased from Nova Solar Capital or leased from Solar Scotia Energy (the solar CEDIF) in the 2018 season. The customer will purchase or lease the solar installation, but the battery backup will be provided at no cost to the customer and left installed for their continued use during its operating life. On completion of commissioning, the battery backup system will become the property of the customer. We would like to receive continued occasional performance updates as part of our test program.
The Nova Scotia Community College carries out research in renewable energy and we anticipate delegating to them the choice of site and we hope to work with them in designing the test program and monitoring regime. This test system is only available for one installation in our first round of new installations in 2018, and would be located somewhere within the Annapolis Valley, South Shore or HRM for monitoring purposes.
What is a Battery Backup System?
A grid-tied solar PV installation uses net-metering so that power generated in excess of what is consumed in the home can be fed back to the power grid to NS Power – essentially using the grid as your storage device - so you get the benefit of every kilowatt you create, either at the time of production or as a credit from NSP. However, when the grid goes down so does your solar as the micro-inverters must sense the grid in order to operate, as power fed back to the grid could cause serious injury to workers working on the power lines. So even on sunny days you would be without power just like everyone else.
A battery backup system uses an inverter charger to take AC power from the grid or the solar array (or from a gas/diesel generator if you have one) into storage in a set of deep-cycle batteries. This is called a “Grid-Tied AC Coupled” system. If the grid goes down, the backup system is isolated from the grid and the inverter uses the battery backup to signal the micro inverters in the solar array that they can deliver electricity. The solar electricity is then used to power essential home services such as lighting, the fan on a forced air oil furnace, fridge/freezer etc or a TV. If the solar is not producing sufficient power, or it’s dark, the solar power is supplemented by power drawn from the battery backup or from a plug-in generator. If it’s dark, the battery storage is recharged from the solar array the next day with any excess power left over after essential loads are met. In principle, and depending on loads, the combination of the solar array and battery backup can keep these essential home electrical services operating for days or even weeks. When grid power is restored, the entire installation will be restored to grid connection. The diagram above shows the main components.
Battery backup systems were originally designed for off-grid applications using string inverter technology but the system we plan to install is designed to work with a modern grid-tied micro inverter system and includes, provisionally, the following components:
- Inverter charger unit. (Magnum Energy MSPAE-4024)
- AC Load centre with breakers; for essential circuits- lights, refrigerator, water pump etc
- Mini Panel with isolation breakers (Magnum MMP175-30D mini)
- Magnum Energy ME-RTR inverter remote panel
- 8 Series/Parallel Batteries 24VDC@920Ah or 48VDC@460Ah (Rolls Surrette S6-460AGM)
- Battery monitor w/shunt (Magnum ME-BMK )
- Surge suppression Device (to protect from lightning strikes and power surges)
The approximate installed retail value is about $12,000 plus taxes. The system will be installed with a 12 month installation warranty from Nova Solar Capital and will be subject to manufacturers’ warranties on materials.
Contact us if you would like to participate or have any questions. We anticipate finalizing the first group very soon in order to get the bulk hardware ordering completed to allow the installations to be underway in late June/July.
Phone: 902 812 1050 or email: firstname.lastname@example.org