certain project company investments, increased financing costs and/or difficulty obtaining financing.
Renewable energy sources in Canada benefit from federal and provincial incentives, such as RPS programs, accelerated cost recovery deductions allowed for tax purposes, the availability of offtake agreements through RPS and the Ontario FIT program, and other commercially oriented incentives. Renewable energy sources in Chile benefit from an RPS program. Any adverse change to, or the elimination of, these incentives could have a material adverse effect on our business and our future growth prospects.
We are also subject to laws and regulations that are applicable to business entities generally, including local, state and federal tax laws. As discussed in Government Incentives and Legislation within Item 1. Business, on December 22, 2017, the U.S. government enacted the Tax Act, which contains several provisions that positively and negatively impact our business and operations. If any of the laws or governmental regulations or policies that support renewable energy change, or if we are subject to changes to other existing laws or regulations or new laws or regulation that impact our tax position, increase our compliance costs, are burdensome or otherwise negatively impact our business, such new or changed laws or regulations may have a material adverse effect on our business, financial condition, results of operations and cash flows.
Maintenance, expansion and refurbishment of renewable energy facilities involve significant risks that could result in unplanned power outages or reduced output.
Our facilities may require periodic upgrading and improvement. Any unexpected operational or mechanical failure, including failure associated with breakdowns and forced outages, and any decreased operational or management performance, could reduce our facilities’ generating capacity below expected levels, reducing our revenues and jeopardizing our ability to pay dividends to holders of our Class A common stock at forecasted levels or at all. Incomplete performance by us or third parties under O&M agreements may increase the risks of operational or mechanical failure of our facilities. Degradation of the performance of our renewable energy facilities provided for in the related PPAs may also reduce our revenues. Unanticipated capital expenditures associated with maintaining, upgrading or repairing our facilities may also reduce profitability.
We may also choose to refurbish or upgrade our facilities based on our assessment that such activity will provide adequate financial returns and key assumptions underpinning a decision to make such an investment may prove incorrect, including assumptions regarding construction costs, timing, available financing and future power prices. This could have a material adverse effect on our business, financial condition, results of operations and cash flows.
Moreover, spare parts for wind turbines and solar facilities and key pieces of equipment may be hard to acquire or unavailable to us. Sources of some significant spare parts and other equipment are located outside of North America and the other jurisdictions in which we operate. If we were to experience a shortage of or inability to acquire critical spare parts we could incur significant delays in returning facilities to full operation, which could negatively impact our business financial condition, results of operations and cash flows.
Developers of renewable energy facilities depend on a limited number of suppliers of solar panels, inverters, module turbines, towers and other system components and turbines and other equipment associated with wind power plants. Any shortage, delay or component price change from these suppliers could result in construction or installation delays, which could affect the number of renewable energy facilities we are able to acquire in the future.
There have been periods of industry-wide shortage of key components, including solar panels and wind turbines, in times of rapid industry growth. The manufacturing infrastructure for some of these components has a long lead time, requires significant capital investment and relies on the continued availability of key commodity materials, potentially resulting in an inability to meet demand for these components. In addition, the United States government has imposed tariffs on imported solar cells and modules. The tariff begins at 30% in 2018 and declines to 25%, 20% and 15% in 2019, 2020 and 2021, respectively. The first 2.5 gigawatts of imported solar cells are exempted from these tariffs. If project developers purchase solar panels containing cells manufactured in China, our purchase price for renewable energy facilities may reflect the tariff penalties mentioned above. A shortage of key commodity materials could also lead to a reduction in the number of renewable energy facilities that we may have the opportunity to acquire in the future, or delay or increase the costs of acquisitions.
We may incur unexpected expenses if the suppliers of components in our renewable energy facilities default in their warranty obligations.
The solar panels, inverters, modules and other system components utilized in our solar generation facilities are generally covered by manufacturers’ warranties, which typically range from 5 to 20 years. When purchasing wind turbines, the purchaser will enter into warranty agreements with the manufacturer which typically expire within two to five years after the