The underlying objective of the paper is to identify and evaluate in the research process vital factors that impact the development of design and construction enterprises of photovoltaic farms on the energy markets, in particular narrowed down to renewable energy sources (RES) markets, including energy coming from photovoltaic sources. The first part of the paper, the epistemological one, introduces a scientific discourse pertaining to conditionings and restrictions related to RES markets in the dimensions of sustainable development. This has been done with the use of literature query, legislative and administrative acts, and reports drawn up for the European Commission. In this reference, we summarized the EU’s essential measures aimed at promoting the idea of sustainability. The second part of the paper, the empirical one, presents a summary of the results obtained within the research pertaining to “opportunities and threats in managing projects of photovoltaic farms in production enterprises of energy appliances”. The research was conducted in a group of 24 design and construction enterprises of photovoltaic farms. The concentration of the research, in the context of the underlying objective of this paper, pertained to the aggregation and evaluation of selected factors that stimulate the development and competitiveness of construction projects and the implementation of photovoltaic farms. We considered the hierarchy of strategic objectives of the investigated enterprises and selected threats to their market position. Two primary criteria were adopted to aggregate and evaluate vital factors that impact the development of design and construction enterprises of PV farms. The first of them is the qualitative one—top scores, weighted averages of respondent evaluations on the five-point Likert scale. The second one is the quantitative criterion—number of indications N ≥ 22 of the respondents (over 90%). A measurable value of the paper is the scientific discourse pertaining to dimensions of competitiveness of the investigated and analyzed enterprises on the RES market, in particular narrowed down to photovoltaic farms.