On Grid Off Grid Energy Solutions

What is an off grid / on grid energy solution

A hybrid off grid / on grid solution uses a combination of technologies to optimise your energy supply, minimise costs and save carbon. We predict this type of energy solution will become increasingly commonplace as businesses look to secure a safe supply of clean energy, reduce dependence on a costly and potentially intermittent grid supply, reduce their carbon footprint and reduce their overall energy costs.

The hybrid off grid / on grid solution provides benefits in many situations but really comes into its own when used in conjunction with a generator where short periods of high load and prolonged periods of low load are encountered. Just using a diesel generator in this situation wastes valuable power and fuel. Using a hybrid solution in conjunction with a solar PV system can enable long periods of solely renewable power, with intermittent back-up from a grid supply or generator.

The Load Controller looks at the load and what is available from the different generators (solar, diesel generator, battery and the grid) at any one time. Load is supplied from the battery with other generators topping up the battery as required. The Load Controller decides which generator supplies the battery, based on the lowest cost of generation first, then by the load required at any one point.

How does it work?

  1. Normal Load - the battery and the solar PV system provide power, silently and without emissions, with intermittent top-up from the grid or generator if required.
  2. Peak Load - the diesel generator, solar PV system and battery work together to supply the peak load. This arrangement means that the diesel generator does not have to be sized to cope with peak demand and so allows use of a smaller unit
  3. Recharge - the control system switches on the diesel generator to provide power whilst also recharging the battery, using a full load profile that is the most efficient method for a diesel generator. Excess solar power will also recharge the battery during the day. At night the battery can be recharged by the grid if available and if it is cost effective to do so.

Benefits of an Off Grid / On Grid Energy Solution

  • Allows use of a smaller generator that reduces overall operation and maintenance costs
  • Increased fuel efficiency - 30% - 50% saving
  • Greatly increased lifespan of the generator due to reduced operating hours
  • Lower running costs of the generator due to reduced servicing requirements
  • Greatly reduced carbon emissions
  • Enhanced security of supply from multiple power sources
  • An on-site renewable 'green ' energy supply for zero cost after initial outlay
  • Long-life batteries typically 6000 cycles and a 15+ year lifespan
  • Back-up supply where connected to an intermittent grid
  • Instant switch-over - no time lag to start the generator motor
  • No load step issues - 100% power on demand


Reducing diesel generator costs

When you have a large diesel generator that you are only running at a fraction of its capacity, the relative cost is greatly increased. It is far more fuel and cost efficient to run your diesel generator closer to capacity but how do you get around the issue of hugely varying load requirements? This is where the hybrid off grid / on grid solution offers tremendous savings; power can be drawn from a number of sources at peak demand, therefore reducing the overall size of generator required on site and ensuring it operates more efficiently i.e. closer to capacity.