We need to learn how to save and reinvest most of the wealth that we are currently consuming or wasting, so that our children and descendants might have a reasonable life. The ethical foundation for this principle could hardly be clearer. Unfortunately, conventional notions of value, capital, investment and wealth are not useful in this task.

Inappropriate concepts of wealth have led us to ignore opportunities to capture local flows of both renewable and non-renewable forms of energy. Identifying and acting on these opportunities can provide the energy with which we can rebuild capital, as well as provide us with an "income" for our immediate needs.

The most important storages of future value include:

Designed ecological restoration is one of the most common expressions of environmental thinking in affluent countries, and is a valid element in permaculture design when it considers people as an integral part of the restored systems. Ironically, the abandonment of more marginal rural landscapes in many affluent and developing countries due to falling commodity prices, and substitution by intensive fossil fuel subsidised systems, has created "modern wildernesses" on a far larger scale than designed ecological restoration. This abandonment has some negative effects, such as the collapse of traditional water management and erosion control systems as well as an increase in wildfire, but in other places it has allowed nature to rebuild the biological capital of soil, forests and wildlife without input of non-renewable resources.

While low-cost and fossil fuel subsidised models for rebuilding natural capital are important expressions of this principle, we can also think of the collective experience, know-how and technology and software deriving from generations of industrial affluence, as a huge store of wealth which can be redeployed to help create new forms of capital appropriate for energy descent. Much of the optimism about sustainability relates to the application of technology and innovation. Permaculture strategies make use of these opportunities while maintaining a healthy scepticism based on the premise that technological innovation is often a "Trojan horse", recreating the problems in new forms. Apart from the need to discriminate in the use of technology to build new capital assets, technological innovation is itself a storage of wealth that will progressively depreciate during energy descent, albeit at a slower rate than physical assets and infrastructure.

The proverb 'make hay while the sun shines' reminds us that we have limited time to catch and store energy before seasonal or episodic abundance dissipates.