Talk:Solar controller

Scope? Zero-carbon controller in particular. (Merge into SWH?)

What is the scope of this article and the zero-carbon section? In particular, what is a "controller" here?

One might assume the "controller" to be the low power consumption device that controls a solar system, but does not perform a power-hungry role within it, such as being a circulation pump (and the presence of valves would be another question). This is the typical meaning of controller, when browsing product catalogues.

However this article describes a "zero-carbon controller". This would have to be taken as meaning a controller of a type distinct from the usual, so as to reduce some carbon emission from the usual type. The only way I can see a controller as having a measurable carbon footprint would be if the "controller" is assumed to include the circulation pump too. This is a somewhat different controller from the pure-control type. I am unaware of any marketing claims for a "zero carbon" controller that doesn't include a pump - to do so would be the worst sort of greenwashing, as the power consumption and thus carbon footprint of a pure-control device with modern electronics is truly trivial.

There is a pump-based controller on the UK market that is fairly well known, the Solartwin. This is sold on the basis of a claim to being "zero carbon" (I see this personally as true, albeit irrelevant) - carbon issues for the pump power are not at the forefront of my thoughts. The device is simple - a PV panel drives a pump. When the sun is out, the pump circulates. They are certainly simple and have a large number of happy users, so they're certainly a credible device. The drawback is that their panels are necessarily less efficient than good contemporary vacuum collectors.

To improve this article, and especially this section, we need to clarify what its scope is. Are there really pure-control devices selling themselves on the basis of being "zero carbon"? Is a system-level combined pump & controller like the Solartwin within this scope? Andy Dingley (talk) 16:05, 17 August 2011 (UTC)

I came to this article late after the title had been changed to "Solar controller" and I think I (and some editors before me) misinterpreted that title to mean SWH controllers in general, not just PV-powered controllers. After working on it (and renaming the zero-carbon controller section as PV-powered controller) I now realize that the original topic was a PV powered controller/pump combination, specifically Solartwin technology (even though there are other manufacturers of this type of equipment).

Now that I have this new understanding, I think we should merge salient parts of the PV-powered section into Solar water heating, where controllers and pumps are already covered pretty well, and delete this page. Jojalozzo 16:57, 20 August 2011 (UTC)

One issue with solar controllers is whether they control mains powered solar heating pumps or PV powered ones. Another is whether the controllers are mains powered or PV powered themselves. Controllers control pumps and the power consumption of the pumps used in solar thermal systems is far from trivial, with research in UK showing that 40-80 kWh pa is common. Barry Johnston 13 March 2012. 79.123.65.62 (talk) 14:12, 13 March 2012 (UTC)

Much of that content was removed around August 2011. Not IMHO an improvement. Andy Dingley (talk) 23:06, 13 March 2012 (UTC)

• Oppose merge – distinct subjects. Will expand and diverge further over time. Put the effort into growth, not consolidation. The Transhumanist 10:42, 25 May 2012 (UTC)