I haven’t blogged about the solar farm for a little while because to be honest there has not been much to report (which is good! this is supposed to be a very stable low-maintenance project!) but I thought I would briefly update the blog to mention communications upgrades and a new PPA.
The site has multiple means of communication, because we need to be able to connect to, and monitor the CCTV cameras, we need reporting from the meter that actually determines how much we get paid (which is reported by a neutral 3rd party who charge a frankly comical amount just to read a single number every 30 minutes and report it), and we also need (or rather we like to have…) reporting from each inverter on the site to tell us the status of each inverter, and indeed each string. When I share the really cool charts and breakdowns with a ton of data, thats from the inverters. This measures DC power, at the inverters, before its converted and then sent some small but noticeable distance along underground cables to the site substation containing the site meter. Because some power is lost in conversion and transmission, the two meter readings are not the same.
Anyway… all of that stuff has to communicate off-site somehow, and its all routed through an aerial on the top of the substation. Its a bad aerial, and it uses a mobile phone connection which sucks. The site is somewhere quite remote and mobile phone coverage isn’t that good. As a result, often the signal is below 25% strength, and we get gaps in the data. The final generation readings are always there, but losing ‘sight’ of the plant is no fun, so we recently had all that comms stuff upgraded. The site now has a constant 48-49% signal strength which is good to see. This cost me unexpected money, but coincided with a maintenance check so the costs of sending people to site were not included.
In other news, we have signed a 2 year PPA (power purchase agreement) again with Ovo. That starts in November and runs out in November 2027. At that point we may stay with them, or switch if anyone offers a higher rate. One of the perverse things about owning a power station is that prices change every 30 minutes, but when you agree a price, it will then be fixed for years. Its tricky, because you are basically watching a fluctuating stock-ticker like price, but where you have to MANUALLY email people to ask for new quotes, and then pick your moment. There are services that offer more visibility into price trends, but I can’t afford them really… You can get 1 year, 2 or 3 year PPAs. I chose 2 years as the 3 year price looked pretty low :(.
And to be honest the actual ‘energy’ price part of it is only about 65-70% of what you get paid anyway. Some of it is benefits accrued through being a remote site, or a site where extra generation is beneficial, and some of it is discounts for having consumption near generation (so you put no strain on the distribution or transmission lines). Basically if you can find a site on some remote island with tons of local businesses and houses needing more power, then go for it. Anything to avoid upgrading the transmission network, apparently! How exactly you are supposed to guess those value pre-build is beyond me. There are probably expensive consultants, or you have to know who to ask and how to ask it.
Price-wise we are roughly the same as we were for our first year. Its… ok. Its not going to make some huge ROI, but its not losing us money either. I did actually pay out some actual company dividends for the first time (OMG), although it will be another few months until I can look at proper accounts and do a real analysis of whether or not we make enough in profits to make that an annual thing… I think larger sites have way better economics.