Solar hot water panels on my roof in 2013.
Two years ago I torn a perfectly functional solar thermal system from my roof. It has been there for a decade and is dutifully waiting about 70% of my water with the heat of the sun (the rest was increased by gas).
I removed it to use the precious roof space for something better-a row of highly efficient REC solar modules.
Then I removed the gas amplifier and exchanged it for a heat pump with hot water. Why? With three electric vehicles I needed more cheap solar power, the heat pump technology had improved to be quiet and reliable, and frankly, thermal water water is on the way outside.
Before: My roof with solar hot water and 6 kW Tindo panels (top)
After: 14 KW Rec sun collectors, Tindo, moved to the E&S roof (below).
Solar therma goes down the drainage
If you installed solar thermal heating panels a decade ago, you probably felt pretty complacent. It was the most efficient way to get hot water with the sun, and it made a large dent in its gas or electricity bills. But the economy has changed dramatically.
A heat pump system that runs with a cheap solar power does a solar thermal system in almost every respect. It is 100% electrical, easier to install and wait, hot water does not drop out, if it is too sunny, can store solar energy to consume at night when powered by PV, or to run with electricity from off-peak power network and cheaper. You can also use your roof space for the most valuable properties in Australian energy: more solar PV.
Heat pumps against midnight shower
But heat pumps are not perfect.
I live with three teenagers who enjoy all 45-minute showers. Usually around midnight. If I want a hot shower in the morning, I have to increase the hot water in the early hours. The bad news? I can’t do that directly with solar power. The good news? The heat pump is so efficient that my battery can easily strengthen it with stored solar.
If I didn’t have a battery, I would program it so that I would increase between 1 and 5 a.m. if I have electricity outside the parcel grid.
Standing next to my Reclaim heat pump and waiting for my teenagers to be ready in the bathroom.
Switch on the tap, switch off the gas
The layer was not just about hot water. This old gas amplifier was one of the last things that tied me to a gas connection. Replacing with a heat pump meant that I could finally scrap the gas knife. I also had to replace the gas stove with induction. This turned out to be a big upgrade in itself – cooking on gas after an induction hob is about as much fun as driving on diesel after owning an EV.
Solar therma evaporates slowly
Solar thermal hot water does not disappear overnight. Some systems will take for decades. But new installations? You will continue to shrink. When PV was expensive, the solar thermal energy made sense. But now? Heat pumps + PV have won the fight to give them a hot shower.
I am so sure that I not only fell the solar thermal energy on my roof, but also an entire website that I had developed this once pioneering work.
Instead, Solarquotes offers a growing number of advice on hot water heat pumps, including video explanators. From last week we now offer up to three quotes for heat pumps from verified installers.
I pulled my solar hot water panels from the roof for the same reason why I no longer use a fax machine1: The technology has developed further. Fifteen years ago both were essential technologies. Today they belong to a museum.
Phase shift is a weekly opinion column of the Solarquotes founder Finn Peacock, in which he shares his views on all things at home with electrification.
Footnot
- Funny fact: When I started solar quotes, I sent many queries by fax! ↩
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