for solar panels you need silicon with 99.99% degree purity. (10^-4 parts of impurities) you don’t get that easily with medieval peasant technology. you need a high-tech vacuum chamber and some chemical to do the purification for you, and also repeated heating/cooling down. Then you need to spray the heated gaseous silicon on a surface and let it cool down slowly so it crystallizes …
And for the steel engine you’d need an advanced forge as well as the raw minerals with sufficient purity. As well as either coal or tons of wood
for solar panels you need silicon with 99.99% degree purity. (10^-4 parts of impurities) you don’t get that easily with medieval peasant technology. you need a high-tech vacuum chamber and some chemical to do the purification for you, and also repeated heating/cooling down. Then you need to spray the heated gaseous silicon on a surface and let it cool down slowly so it crystallizes …
I don’t think we’d be back to middle ages tech, it would be more like industrial revolution right?