This dissertation examines the influence of attitudes, beliefs, and preferences of energy industry practitioners on investment decision-making with regard to fuel choice for new electric power plants. The conclusions are based on in-depth interviews and an extensive online survey I conducted of 600-800 energy professionals in the U.S. power sector. Chapter 1 analyzes the impact of policy uncertainty on investment decision-making in renewable energy, using the federal production tax credit (PTC) and wind energy investment as an example. It is generally understood that the pattern of repeated expiration and short-term renewal of the PTC causes a boom-bust cycle in wind power plant investment in the U.S. This on-off pattern is detrimental to the wind industry, since ramp-up and ramp-down costs are high, and players are deterred from making long-term investments. The widely held belief that the severe downturn in investment during "off" years implies that wind power is unviable without the PTC turns out to be unsubstantiated: this chapter demonstrates that it is not the absence of the PTC that causes the investment downturn during "off" years, but rather the uncertainty over its return. Specifically, it is the dynamic of power purchase agreement negotiations in the face of PTC renewal uncertainty that drives investment volatility. This suggests that reducing regulatory uncertainty is a crucial component of effective renewable energy policy. The PTC as currently structured is not the only means, existing or potential, for encouraging wind power investment. Using data from my survey, various alternative policy incentives are considered and compared in terms of their perceived reliability for supporting long-term investment. Chapter 2 introduces the concept of expected payment of carbon as a factor in investment decision-making. The notion of carbon risk (the financial risk associated with CO2 emissions under potential climate change policy) is usually incorporated into investment decision-making by including a cost of carbon in the budget analysis. Most existing literature uses the expected price of carbon as a proxy for this cost, where expected price is a weighted average of various scenarios, often comparing policy proposals and representing either the price of traded permits or level of carbon tax, depending on the type of policy. The literature focuses on the minimum price of carbon required to influence power plant investment decisions. In contrast, this chapter introduces expected payment as a more accurate measure of carbon cost as it is perceived by industry practitioners. The expected payment of carbon is the expected price of carbon times the probability that this cost would actually be faced in the case of a particular investment. This concept helps explain both the 2005-2006 surge of activity in coal-fired power plant development and the subsequent decline in that interest. The energy industry has been slow to move away from fossil fuels and towards renewable resources. In chapter 3 I find evidence for a cognitive bias that plays a role in this momentum. Energy executives' expectations of future energy prices are strongly correlated with their own preferences, which I document for the case of natural gas prices. This is an example of wishful expectations, a form of overconfidence in which people are excessively optimistic over uncontrollable future outcomes. This implies energy executives with strong exposure to fossil fuels are excessively optimistic on future prices and so continue to invest despite the presence of superior alternatives.