In this paper, we introduce an electricity market model and use it to explore the effect of climate change on electricity output and prices. It is calibrated to the New Zealand Electricity Market, and includes multiple generation fuels, uncertain fuel availability, and storage options. The model is formulated in continuous time, which mimics the many short trading periods that are common to electricity spot markets, while properly incorporating forward-looking generation decision making. Specifically, it is used to estimate the effects of changes that may arise in characteristics of fuels -water and gas- as a consequence of climate change and climate change policies. The model does this under the polar cases of a competitive market structure and monopoly. There are three key findings from the results. First, the results illustrate the importance of allowing for volatility and including management of storage in electricity market models. Second, they suggest that reductions in average hydro fuel availability will reduce welfare significantly. Increases in the volatility of hydro fuel availability will also affect welfare, but to a very small extent. Third, the value of reservoir expansion is sensitive to the distribution of hydro fuel availability. Finally, the effects of a carbon tax are also reported.