We have three reportable segments: (i) Solar, (ii) Wind and (iii) Regulated Solar and Wind. These segments, which constitute the Company’s entire portfolio of renewable energy facilities have been determined based on the management approach. The management approach designates the internal reporting used by management for making decisions and assessing performance as the source of the reportable segments. Our reportable segments are comprised of operating segments. An operating segment is defined as a component of an enterprise that engages in business activities from which it may earn revenues and incur expenses, and that has discrete financial information that is regularly reviewed by the chief operating decision makers in deciding how to allocate resources. Portugal Wind, Uruguay Wind, and the Regulated Spanish Solar and Wind segments are new operating segments that were added during the second quarter of 2018, and include all of Saeta’s operations. Consequently, the Company’s operating segments consist of: (i) Distributed Generation, North America Utility and International Utility, which are aggregated into the Solar reportable segment, (ii) Northeast Wind, Central Wind, Texas Wind, Hawaii Wind, Portugal Wind and Uruguay Wind operating segments, which are aggregated into the Wind reportable segment, and (iii) the Regulated Spanish Solar and Wind operating segments, which are aggregated within the Regulated Solar and Wind reportable segment. These operating segments have been aggregated into reportable segments as they have similar economic characteristics and meet all applicable aggregation criteria. We also have corporate expenses which include general and administrative expenses, acquisition costs, interest expense on corporate-level indebtedness, stock-based compensation and depreciation, accretion and amortization expense. All net operating revenues for the years ended December 31, 2018, 2017 and 2016 were earned by our reportable segments from external customers in the United States (including Puerto Rico), Canada, Spain, Portugal, the United Kingdom, Uruguay and Chile.
For the year ended December 31, 2018, TerraForm Power earned an aggregate of $186.7 million from the Spanish Electricity System, including $127.9 million from the Comisión Nacional de los Mercados y la Competencia (“CMNC”), which represented 16.7% of our 2018 consolidated operating revenues. The role of the CMNC is to collect funds payable, mainly from the tariffs to end user customers, and is responsible for the calculation and the settlement of regulated payments. We believe this concentration risk is mitigated by, among other things, the indirect support of the Spanish government for the CNMC’s obligations and for the regulated rate system more generally. Other than the CMNC in Spain, there is no other single customer from which we generated more than 10% of our revenues for the year ended December 31, 2018. In California, where a portion of our solar generation fleet is located, we generated certain revenues from three public utilities located in the state. These three public utilities, in aggregate, accounted for approximately 13.6% of our consolidated operating revenues for the year ended December 31, 2018.
As of December 31, 2018, we had 177 full-time employees, the majority of whom were located in the United States. The governance agreements entered into between the Company and Brookfield in connection with the Merger and Sponsorship Transaction provide for Brookfield to appoint our Chief Executive Officer, Chief Financial Officer and General Counsel. These three executive officers are not employees of the Company and their services are provided pursuant to the Brookfield MSA.
Health, Safety, Security & Environment
We promote a culture of health, safety, security and environmental leadership. We strive to achieve excellence in safety performance and to be recognized as an industry leader in accident prevention. Our overall objective is to incur zero high risk safety incidents and zero lost time injuries. We have adopted a Health, Safety, Security and Environmental (“HSS&E”) policy that includes a framework for oversight, compliance, compliance audits and the sharing of best practices both within our operations and with other affiliates of Brookfield. We maintain an HSS&E Steering Committee and require all employees, contractors, agents and others involved in our operations to comply with our established HSS&E practices.
We make available free of charge through our website (www.terraformpower.com) the reports we file with the SEC, including our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. The SEC maintains an internet site containing these reports and proxy and information statements at www.sec.gov.
The following corporate governance documents are posted on our website at www.terraformpower.com: