Bespoke off-grid energy systems using standard UFL components
If you’ve read much of our website, you will realise that at UFL, we do things a little differently. We don’t believe that one system fits all. How can it? Each site has it’s own widely varying renewables and widely varying load requirements.
It would be very easy for us to take all the market-leading ‘off the shelf’ components, put them in a 10′ shipping container and say that one system fits all. As we see it, the problem with this approach is ‘price’ and ‘complexity’.
The traditional approach
The standard off-grid power system uses an AC generator and an expensive and sophisticated inverter-charger, leading to the following issues:-
- an unnecessarily oversized AC generator (‘off the shelf’ durable AC generators do not come in sizes small enough to match the needs of most domestic energy systems). A good inverter-charger will ensure that the generator is run fully-loaded meaning that it will run efficiently but short and frequent cold starts will reduce engine life and increase servicing costs.
- a need for an additional control system to allow the user to make simple changes to the inverter-charger and even to display basic information.
- the inverter-charger becomes yet another (and unnecessary) single point of failure. Failure comes in many forms – market-leading inverter-chargers are very robust, but through their extreme sophistication, can switch themselves into a ‘safety mode’ requiring an Engineer to come on-site to fix the problem.
The UFL approach
Firstly, we put domestic hot water heating and space heating at the heart of our designs, rather than offer engine heat recovery as a bolt-on option at the end. When you’re focussed on your carbon footprint and all your running costs, why consume 1000L of kerosene a year when your engine is already pumping out 70% of the fuel energy it uses?
In the average UK home, heating costs are between 2 and 3 times the cost of electricity. This is why we at UFL include heat management/generation at the core of our energy system designs.
Secondly, we don’t use inverter-chargers, so we have immediately avoided complexity and a single point of failure. Instead, we use our own DC generator to do the battery charging and a flexible array of lower cost inverters (generally one per consumer unit circuit).
Finally, the battery bank technology we use (Lithium Iron Phosphate) is charged using the simplest charge algorithm and is happy being left in half-charged state meaning that there will always be capacity available for renewable energy (wind, hydro and PV) input.
Our battery technology is 99% efficient compared with 75 to 80% in lead acid batteries. If the electrical efficiency of your generator is 30% (which is quite good), a 75% efficient battery bank will reduce that generator efficiency to 22.5% (which is abysmal).
Through our KISS (Keep it Simple Stupid) approach to domestic energy system design, we can design your system so that it is cheaper to buy, cheaper to run and service, and more reliable than the traditional approach.