Sample Size

I'm working on my empirical part of Master thesis. I'm trying to test my hypotheses regarding effects of increased generation of Renewable energy on Energy import (increased Renewable sources should decrease dependency on energy imported)
Linear regression should be the best choice, but problem occurs at sample size, because I only have appropriate data for 26 years (N=26). What do you suggest, should I create linear regression anyway or is it better to use other method to test this hypothesis?
I have data on :
- Electricity generation from renewable sources from 1990-2016
- Net energy import from 1990-2016

Thanks for your answers,