The article highlights the challenges and proposes solutions for integrating solar PV systems into historic buildings. The essential factors and their constituents (excluding natural and orientation), which limit the integration of solar electrical systems (PV) into historical buildings, are analyzed. It proposes its own view of the degree of value of territories and the most historic buildings and associated legal restrictions. The main properties of photovoltaic cells that influence the choice of solutions for integration into buildings of various categories in territories of different values are determined. The suitability for the integration of the visible parts of solar photovoltaic systems is assessed in terms of their selection and adaptation of their properties in the conditions of the historical environment. The visibility of photovoltaic cells installed on the outer shell of building structures from public spaces is investigated as an aesthetic component of integration, initial conditions, approaches and tools for its analysis. A bunch of value features of territories and buildings with a visual and aesthetic component is proposed as the basis for resolving issues related to determining the level of “criticality of the environment” or “sensitivity of the historical context”. Historical buildings of all categories of value make up a significant part of the construction fund of our state. They are the hallmark of our historic cities. But their normal functioning, and possibly their existence, primarily depends on the preservation of their utilitarian function and adaptation to new energy realities. In order to preserve the architectural heritage for future generations, it is necessary to find such approaches and solutions in the energy modernization of historic buildings that will simultaneously increase comfort, reduce energy bills and minimize environmental impact - to preserve historical and aesthetic values.