There is an important difference between the terms “renewable resource” and “renewable technology.” “Renewable technology” commonly refers to the set of tools, materials, and methods that enables people to use renewable resources to perform a certain function.
Renewable technologies often rely on the use of non-renewable resources. For example, a technology that converts renewable (replenished) energy from the Sun into electricity could include non-renewable metals and silicon that have been processed using non-renewable chemical products; in addition, it is likely to depend on a large array of non-renewable technologies, including transportation and electrical distribution.
We can judge just how “renewable” a technology really is by assessing the fraction of total resources it uses that are renewable (as defined by the Renewable R's). The optimum technology will recycle all of the materials it uses (if not the preferably replenished resources it processes) into like or other uses (replacement), and if necessary include components that are functional over a very long time (reliable).
Currently life is the only truly close to optimum technology, and Nature's biosphere provides this technology practically for free. The result of many millennia of development and testing through evolution, it would be very expensive (if not impossible) for us to create such a technology on our own. Alternatives on the horizon such as biotechnology and nanotechnology, one involving tinkering with existing life and the other with something totally different, carry the risk of inadequate testing leading to potential disaster.