Our energy systems are terribly inefficient. Take coal power for instance. We dig up coal, process it, ship it, burn it, heat a boiler, use the stream to turn a turbine that makes electricity, then send that electricity down powerlines to your home.
At every step we lose energy. By the time you turn on a light, about two-thirds of the power has been lost.
Consider a wind turbine though. If you compare it to coal, then you can cut out most of the steps. You end up with turn a turbine, deliver electricity to your home. By cutting out so many steps we’ve reduced the inefficiency of delivering energy to your home.
Why Does Energy Inefficiency Matter?
This lost energy matters most when it comes to how we talk about the switch to renewables like solar and wind. When we talk about replacing the energy created by legacy systems, we’re often talking about all the energy. That includes the energy lost during production and transportation. Renewables are much more efficient though. It’s more akin to the diagram below.
In this scenario we’ve discussed, the battery would be replaced with the light in your home. I’m sure you get the idea though. In the screenshot below (take from the DW mini-doco called The mind-blowing thing we get WRONG about energy (which we have embedded below) shows the lost energy from using coal and gas to produce electricity. If that lost energy becomes part of the discussion about swapping to renewables then we’ve making a mistake. We’re calculating our energy needs based on a figure that doesn’t correlate with our future under renewable energy.
This is good news
This is good news because, as is explained in the video, don’t have to replace all our current energy. We only have to replace about half of it. This makes the pathway forward toward a carbon neutral future much more achievable.
What About solar
Rooftop solar is one of the most efficient forms of energy. There are no losses from power transmission. It is true that solar panels are about 20% efficient but the important thing is that you can deliver your home’s energy needs directly to your home.
As discussed in the video, electric cars are about 90% efficient (compared to 30% for ICE cars). That means if you charge you car at home from your own solar you’re maximising your energy efficiency for both home and transport.
Watch the video
We’ve given you a small summary here. Watch the video below for the full scoop.
