What countries favour people who want to live a sustainable lifestyle?

If you're currently in Western Europe, then Eastern European countries may be very interesting for you to look at, because compared to Western Europe:

1. The cost of living tends to be lower, so you could invest more of your savings into alternative technologies such as solar energy
2. Cost of property tends to be lower (both housing and land)
3. There's generally more property available in villages, because young people tend to want to stay in the towns (or even move abroad), so you have more choice
4. Regulations tend to be more relaxed
5. A self-sufficient lifestyle is still more widely practised by local people
6. Nature tends to be more pristine, meaning there are more opportunities to forage for food

We're from Western Europe and have been living in Bulgaria now for over 5 years. I'll share my experience regarding the above points to give you a deeper insight in this country. I believe the situation is very similar in Romania, but cannot speak from personal experience.

1: Cost of living: in 2016 the cost of living in index for Spain is 56.11 (which is much lower already than most Western European countries), and for Bulgaria it's 36.36 (which is much lower again). Source: http://www.numbeo.com/cost-of-living/rankings_by_country.jsp.

2: Cost of property: in 2016 in many Bulgarian villages it's possible to buy an old house from between 10.000 and 20.000 Euros upwards. These would be houses that need work, but they are liveable. many houses have a decent sized garden (think 500 to 1000 m2 minimum). If you need more land for growing food, I'd consider not buying that, but using old communal land. Many villages have this and it can be rented cheaply or worked freely.

3: Availability of property: everywhere in Bulgaria younger people tend to want to live in the towns (where most of the work is), leaving the villages (and there are many) to the elderly. When occupants die properties are often left uninhabited for long periods of time.

4: Regulations: compared to Western Europe the attitude towards what you want to do with your property is much more 'laisser faire / let it be'. If you want to build a compost loo in your garden, you just do it. Want to install solar panels? Go for it. Building a lean-to for storing straw-bales? No problem. Want to dig a pond in your garden? Sure. Don't get me wrong, there certainly are rules and regulations, but for relatively small things the attitude of everyone is: just do it. As long as it's sensible and it blends in, no-one really cares.

5: Self-sufficient lifestyle: in the villages older people tend to be fairly self-sufficient. Almost everyone grows a garden that they use to feed themselvesand sometimes their family throughout the year. Canning and bottling all kinds of foods is very common. Many people keep animals (most commonly chickens and bees, but also geese, goats, sheep, donkeys, horses, cows, pigs, etc.). And these things are totally normal and even applauded. Bulgarians tend to be proud of their gardens.

6: Pristine nature: Eastern European countries are much less densely populated than most Western European countries. With an average population density of 69 people per km2, Bulgaria is one of the lesser densely populated countries in Europe (source: https://en.wikipedia.org/wiki/Area_and_population_of_European_countries). This leaves much more room for nature. I've tried to find you statistics on the level of biodiversity here, but they're not very well recorded, so I can only speak from personal observations. When I compare Bulgaria's nature to that of the Netherlands and the UK (countries I've both lived in), there's just much more nature here. Commercial agriculture is also big in Bulgaria, and you will see vast areas of monoculture, but at the same time in areas less accessible to humans nature still just does its thing.

Some more info:

The climate here is continental with warm summers and cold winters. We're experimenting with growing our own food and have come to the conclusion that with permaculture techniques it's possible to grow our own food year-round. We're not self-sufficient at all food-wise, because we choose to focus on other things also, but it would be possible for us.

There weather is generally sunny, which is great if you're looking into producing your own energy from the sun. But there's also plenty of rain, which is great for growing food.

There are many natural springs also, so it's usually quite easy to get good drinking water (tap water is considered safe also by the way).

Another consideration if you're now in Spain is that Bulgaria is (like Spain) a EU country, which makes settling here easier.

I hope this helps :)