Grid Tie Solar With Battery Backup
Grid Tie Solar with Generator Backup
There are many different opinions on this issue. At Emerald Coast Solar, we come down in favor of generators. Some companies and individuals agree with us, while others are in favor of batteries. We want to try to offer an unbiased review of the pros and cons for each system.
As with any purchase, there are good products and there are cheap products. We are not going to look at the cheap end of the spectrum for either generators or battery backup systems. They are exactly that, cheap products. If you want something that will last, you will have to spend the money on a good product.
First, let’s look at functionality. Does the system match your home electrical?
Portable generator over 6000 watts Yes, they usually have at least a 30 amp, 220 breaker
Whole home backup generator Yes, wired directly into
home electrical system
Battery Backup No, is usually 110 volt. Will not power 220 appliances.
Needs additional equipment to power 220.
Does the solar system work with the backup system?
Portable generator over 6000 watts No, the solar needs to be disconnected when generator is in operation.
Whole home backup generator No, the solar needs to be disconnected when generator is in operation. This occurs automatically.
Battery Backup Yes, designed to work with the solar system.
Is the backup for critical items or whole home?
Portable generator over 6000 watts Critical only, may be able to run some air conditioning
Whole home backup generator Depending on size, should run entire house for extended periods
Battery Backup With most affordable systems, is for critical use only and generally short term.
Cost and availability of fuel in emergency?
Portable generator over 6000 watts Runs on gasoline. 50% load good for about 7 hours per tank. Need to have additional fuel on hand for longer emergencies
Whole home backup generator Runs on propane. Can run for days with a full 300 ltr tank. Will need to be refueled.
Battery backup Gets new charge from the solar panels each day there is sunshine. Sized correctly, the solar panels, will continue to operate indefinitely
Does the backup system come on automatically?
Portable generator over 6000 watts No, it needs to be started manually with a key.
Whole home backup generator Yes, and it will auto shut off when power is restored.
Battery backup Yes, and it may auto shut off when power is restored.
Does the system perform self-diagnostic checks?
Portable generator over 6000 watts No, but has little to go wrong if maintained correctly.
Whole home backup generator Yes, and is soon to have monitoring through cell and internet.
Battery backup Possibly, depending on system.
Install and additional equipment?
Portable generator over 6000 watts Usually fairly simple with some electrical cable and a matching plug and breaker for existing home breaker panel. Needs to be used outside with proper ventilation.
Whole home backup generator Requires rewiring of main electrical run. May require additional propane tank and gas lines run to tank. May require construction of cement pad or cement bodega for proper operation and longevity. Needs to be outside with proper ventilation.
Battery backup Requires certain solar inverters to be used. Generally installed concurrent with solar system. Requires tie in to existing existing electrical. Requires battery station and possible separation from the main living areas of house. Requires additional equipment to handle 220 power loads.
Can the backup be run from any solar system?
Portable generator over 6000 watts Yes, the generator is independent of the solar system entirely.
Whole home backup generator Yes, as per above, it is an independent system.
Battery backup Yes and no. In most cases, there are only a few inverters that can handle the battery back up system. Most current grid tie inverters are not designed to handle these. Also, micro-inverter systems (the systems that generate the most power) cannot work with these systems. There is an option to have the battery back up system completely separate from the solar system. This would however, mean the batteries are only charged from CFE power. A problem during a lengthy power outage.
Cost of operation and maintenance?
Portable generator over 6000 watts Cost of fuel and minimal maintenance costs over the life of the unit.
Whole home backup generator Cost of fuel and ongoing maintenance. Recommended maintenance twice per year with major service after each 120 hours of operation.
Battery backup Zero cost for fuel. Regular maintenance required and need to replace batteries on average every 3 to 5 years regardless of use. Some systems do claim 10 years on battery life at major additional cost.
Possible issues in emergency?
Portable generator over 6000 watts Lack of fuel to get through the emergency.
Whole home backup generator As above and possible damage to generator in the event of a hurricane unless properly protected.
Battery backup If the solar panel system is damaged, then the backup will only last for as long as the batteries have a charge. In the event of a hurricane, chances are very good that the solar system will be damaged. This will render the backup useless.
Cost for backup system?
Portable generator over 6000 watts Generac 8000 elite usually under $30,000 pesos including install.
Whole home backup generator Generac has a number of models ranging from under $70,000 pesos including install up to over $200,000 pesos. Median pricing under $120,000 pesos dependent on installation and additional equipment needed.
Battery backup 110-volt systems substantially higher than generator options. 220- volt even more.
As we said, we do favor generator systems. If you are still undecided as to which system is best for you, why not get quotes on each? We would be happy to give you a quote on a solar system with either a portable or whole home generator system. You can then compare these quotes to what is available in grid tie with battery backup.
We are confident that once you see the advantages of a grid tie with generator backup, the decision will be easy.
You can download this document by clicking on the PDF file here