We believe there is significant opportunity to enhance our cash flow through optimizing the performance of our existing assets. As our recently announced long-term service agreements (collectively, the “LTSA”) with an affiliate of General Electric demonstrate, such agreements have the potential to lock in cost savings, provide contractual incentives for achieving our generation targets and increase revenue through deployment of technology. We are currently seeking to execute similar agreements to optimize the performance of our North American solar and European wind fleets.
We continue to develop a robust organic growth pipeline comprised of opportunities to invest in our existing fleet on an accretive basis as well as add-on acquisitions across our scope of operations. We have identified a number of investment opportunities which we believe may be compelling, including asset repowerings, site expansions and adding energy storage to existing sites.
We benefit from Brookfield's deep operational expertise in owning, operating and developing renewable assets, as well as its significant deal sourcing capabilities and access to capital. Brookfield is a leading global alternative asset manager and has a more than 100-year history of owning and operating assets with a focus on renewable power, property, infrastructure and private equity. Brookfield has approximately $47 billion in renewable power assets under management, representing approximately 17,400 MW of generation capacity in 15 countries. It also employs over 2,500 individuals with extensive operating, development and power marketing capabilities and has a demonstrated ability to deploy capital in a disciplined manner, having developed or acquired 13,200 MW of renewable generation capacity since 2012.
Factors that Significantly Affect our Results of Operations and Business
We expect the following factors will affect our results of operations:
Our revenue is primarily a function of the volume of electricity generated and sold by our renewable energy facilities as well as, to a lesser extent, where applicable, the sale of green energy certificates and other environmental attributes related to energy generation. Our current portfolio of renewable energy facilities is generally contracted under long-term PPAs with creditworthy counterparties. As of December 31, 2018, the weighted average remaining life of our PPAs was 13 years. Pricing of the electricity sold under these PPAs is generally fixed for the duration of the contract, although some of our PPAs have price escalators based on an index (such as the consumer price index) or other rates specified in the applicable PPA.
We also generate RECs as we produce electricity. RECs are accounted for as governmental incentives and are not considered output of the underlying renewable energy facilities. These RECs are currently sold pursuant to agreements with third parties and a certain debt holder, and REC revenue under bundled arrangements is recognized as the underlying electricity is generated if the sale has been contracted with the customer. Under the terms of certain debt agreements with a creditor, SRECs are transferred directly to the creditor to reduce principal and interest payments due under solar program loans.
Project operations and generation availability
For our Solar and Wind segments, our revenue is a function of the volume of electricity generated and sold by our renewable energy facilities. The volume of electricity generated and sold by our renewable energy facilities during a particular period is impacted by the number of facilities that have achieved commercial operations, as well as both scheduled and unexpected repair and maintenance required to keep our facilities operational. For some of our plants, particularly our wind plants located in Texas, we sell a portion of the power output of the plant on a merchant basis into the wholesale power markets. Any uncontracted energy sales are dependent on the current or day ahead prices in the power markets. Certain of the wholesale markets have experienced volatility and negative pricing.
For our Regulated Wind and Solar segment, revenue is regulated by the Spanish government. In Spain, renewable electricity producers receive the merchant price for the power they produce and a return on investment payment per MW of installed capacity. For solar plants, there is an additional return on operations payment per MWh produced. This scheme is intended to allow renewable energy producers to recover development costs and obtain a reasonable rate of return on investment. The reasonable return is calculated as the average yield on Spanish government 10-year bonds on the secondary