This paper aims to identify the key determinants of Chilean spot power price and assess their relative importance in recent price decline. To do so, we use a VAR model with weekly data between the years 2015-2016 and variance decomposition analysis to attribute variations of marginal cost to different shocks. The results show that while the availability of water for hydropower and lower fuel prices are important for explaining power spot prices, they only account for 50%-75% of the marginal cost´s variance, leaving 25%-50% to other factors, such as more renewable generation and lower generation from oil sources, among other factors.This paper aims to identify the key determinants of Chilean spot power price and assess their relative importance in recent price decline. To do so, we use a VAR model with weekly data between the years 2015-2016 and variance decomposition analysis to attribute variations of marginal cost to different shocks. The results show that while the availability of water for hydropower and lower fuel prices are important for explaining power spot prices, they only account for 50%-75% of the marginal cost´s variance, leaving 25%-50% to other factors, such as more renewable generation and lower generation from oil sources, among other factors