ON GRID VS OFF THE GRID?

Batteries and other energy storage devices used to store energy, which can be used when needed, for instance in a night time where solar energy is not available. In a stand-alone power system, the energy stored in batteries can be used when energy demand exceeds the output from solar power system for an example on a cloudy day. Let’s look at different solar power systems available in Australia.

Grid connected systems

”A grid connected system” as name this system is grid network (power lines) coupled system. Grid connected energy system converts DC electricity from solar panels, to AC mains power and excess energy feeds it into the grid. It usually consists of the solar modules for generating power, an inverter to convert this power from DC to AC and a meter to record data on both purchased energy from grid as well as exported power. On grid connected system, if there is a mains grid power failure, Inverter disconnects entire system from the grid and energy from solar panels is not available. Battery banks can be used in this system with an appropriate hybrid inverter, may work as a Hybrid power supply to make energy available during a power outage for all or some of the electrical loads in a home or business. Although costs are currently dear due to use of extra components required, possibly it also can be used in a smart way to enable one of the following options:

Excess energy stored for use on site and used at a later stage for homes where feed- in tariff is not so great.

During an off peak times, energy to be stored from Grid at a lower prices(off peak rates) utilized during peak times where energy is charged at a higher rate (only for the homes connected with off peak)



System components:

  • Solar panels
  • Inverter
  • Electrical safety gear eg. fuses, breakers, conduit

Off-Grid systems also known as Stand Alone system

Off-grid system is more practical where the grid supply is not available such as remote regional areas where bringing grid to site is not feasible or cost effective. Australia have many sites across the nation have adopted this technology where generation from diesel (or fossil fuel) generators used to power the site. This system is also capable enough getting connected with other optional power sources like wind turbine and other fuel generators for backup power. This system is also a perfect fit for those who is willing to have a supply in remote places where going to off grid is more cost effective than connecting to the electricity grid. Off-grid systems are most common in remote locations without utility service. Off-grid solar systems also can be used for boat, remote agricultural pumps, gates, traffic signs, etc. These systems typically require either a battery bank to store electricity for use as a backup source of energy like a generator, or both. An off-grid solar system must be large enough to produce enough electricity to cover full energy needs of site for multiple days without having charged through solar or other generation. Also the usage must be monitored and kept below the maximum output of the panels and batteries as there is no grid-source to supply excess power.

System components:

  • Solar panels
  • Inverter
  • Batteries for power storage
  • Charge controller (to protect the battery bank from overcharge)
  • Electrical safety gear eg. fuses, breakers, conduit
  • Monitoring system to balance energy consumption with production