My workshop is virtually sealed and light-tight. At least 100mm insulation all round, except thinner on the access door. The lighting costs are less than the otherwise heating needs, by far.
I use a desiccant dehumidifier (only one, currently) as a heat source and for humidity control during the cooler months. Can be cooler in summer months, too. I have a fridge ‘cooling panel’, waiting in the wings, should I need to install it for summer cooling duties.
I had to move in my Centec 2B after dismantling it (too heavy, otherwise!). Nothing wider than 250mm for a 2/2A or 225mm for a 2B, I think. Stand is a different matter, dependent on type!
I have a sectional door. A roller shutter, if space permits, would allow greater roof storage. My lighting is totally of LED type.
A solar powered installation should be considered for the household – can still be viable even with ‘feed in tariffs’ no longer available. No ‘regulation need’ for a ‘certified’ PV installer or new kit, now that the FITS have gone. Only real difficulty is fixing panels to the roof – and at least getting the electrical installation signed off by a qualified electrician.
Cooling and lighting, in a PV-installed dwelling, could cost virtually nothing on the leccy bill during the spring to autumn period.