The answer which we’ve learned on our off-grid journey is observe, learn and plan.
As anyone relying on nothing but solar power will know, there’s only one disadvantage to having 300 days a year of sunshine in Portugal – and that’s the other 65 days without.
When we first moved into the Valley of the Stars, we very quickly learned which power-hungry luxuries to save for the sunshine: one never makes toast while blow drying.
Relying completely on renewable power means learning how to carefully monitor what is being used where, and deciding on contingencies as each cloudy or stormy day arrives.
The more buildings and guests you have, the more power you use and the greater the need for planning and backups.
We looked at the high costs of connecting to the national grid and made a decision to go the sustainable route… to have one very expensive electricity bill at the start and no bills from then on.
Having dodged the late October storm courtesy of a big mountain getting in the way, we were battered by Storm Claudia like everyone else.
Anything coming towards us here in Odemira from the south hits Monchique and Fóia first and leaves us in the rain shadow dropping far fewer millimetres than the apps often predict.
Of course, in dry times, that works against us, and we can never complain about rainfall when we collect water for our lake and our property.
Thankfully, there were no tornados to report and only one small flood, but the first big storm of the winter always serves to sharply switch us back into winter mode of carefully monitoring all our energy consumption.
Opening to guests for the first time this year, we built a system far bigger than we need for most of the year.
We swan through summers barely looking at the solar read out, blessed as we are by enough solar panels to happily ensure our batteries are full every day before breakfast is over – despite the pumps, the power use and all the people.
Even when the days get shorter, we have confidence in our 84 solar panels.
They even work when it’s overcast, but after a storm hits and the clouds persist, we earn our keep as an off-grid resort.
That’s when power monitoring becomes an obsession and we head to a variety of different weather apps to work out what’s going to happen next.
Most of the buildings and pumps have electricity monitors and we’re adding internet-connected switches to save me running up the hill and turning things off in the rain.
But as far as forecasting storms, most predictions for our valley are at best 50/50, and so I channel my inner weatherman, hark back to my Geography degree and start muttering about cold fronts and barometric pressure.
Our favourite apps are Weather Underground and Ventusky, which provide us with some real-time radar and some big-picture predictions as various models plot expected rainfall and front movements by the hour.
After five years, I am starting to learn some patterns, but with everything becoming more unpredictable thanks to global warming, it’s not the easiest to get right.
Storm Claudia was a tricky one – she hung around a lot longer than the usual storms, thanks to being sandwiched between two areas of high pressure in the Atlantic and over mainland Europe.
And she also had a nasty habit of raining all day and then clearing all night – perfect for star gazing but not great for our solar system.
I’m not sure if there’s any science behind it, but we tend to get more rain overnight and at least a little sunshine during each day… and we don’t need much to boost our batteries and regenerate our confidence.
Solar systems give you a percentage of how full or empty the batteries are, but the most accurate measure seems to be the battery voltage – once it drops to 48V, the power goes off.
The key is in keeping a safe margin and staying above 50V – something easily achievable with some tight management and a backup generator.
Despite the days of rain, we stayed well out of the danger zone, and as we watched the sun rise and its rays start reaching our panels – despite the forecast – our overall outlook was even brighter.
The first test is always the toughest as we tweak our pumps and get back into our power-saving routines, but once again, our system passed with flying colours (speaking of flying colours, we’d love to find a decent but affordable wind turbine which can integrate into our Victron solar system… anyone with recommendations, please get in touch!).
With the batteries filling up fast, our trip to Vila de Frades and Vidigueira for the talha opening celebration weekend was back on.
Driving into the interior Alentejo, the skies cleared, the storm headed off into Spain, and we headed into an adega-full of some of the most exciting wines and interesting winemakers.
It was Simon the dog’s 98th birthday (14 human years x 7) and if I ever make it to his age, I’d be more than happy with a day like it: burger and fries, a load of excellent wine, a huge amount of attention and a late-night dance party to finish.
We’ve got the power.
