NOVELTY - An electromagnetic energy harvesting converter (1050) comprises: an enclosure having a front light transmissive cover and a rear cover; a space between the covers; an array of parallel arranged slats (1020); each having a forward face that can receive light directly, and a rear face that can receive light indirectly, and at least one photovoltaic energy converter mounted on at least part of each slat, within the spacing; and a forced air generator arranged to induce air flow (1010) within the enclosure, to remove solar heat from the slats.    USE - As an electromagnetic energy harvesting converter using solar energy, useful as a window system positioned as window beneath ceiling to guide direct sunlight near the ceiling; and as an automated system that responds to energy input or demand for a heat load of a building, having front light transmissive cover integrated as part of a building's weather envelope, and as skylight for the building (claimed) i.e. as a powerskin for night use, for controlling a building; as a rooftop light energy harvesting apparatus; and as portable solar energy system.    ADVANTAGE - The electromagnetic energy harvesting converter provides improved solar energy collection technology with respect to efficiency and cost; as compared to the prior art reflecting optics, or refracting optics that require 2-axis designs and are difficult to mount on the roof. The photovoltaic (PV) cells convert photons into electricity and are used to convert some of the light to electricity, with much of the remaining incoming energy converting to heat. The construction of the slats with concave shapes facing the incoming light, and with appropriate slat orientation; the specularly reflecting concave surface can create a region of higher intensity light on the back side a nearby slat. The use of PV cells in this region allows a smaller, less expensive area of PV cells to be used to generate similar amounts of power. The applying of the PV material to sides of slats facing sun is straightforward; is able to generate heat and electricity, and further provides diffuse skylight and secondarily reflected direct sunlight, which provide useful light to space behind apparatus (e.g. to buildings), and makes this apparatus economically attractive versus many other solar collection systems. Further, air is forced through the cavity containing the warm slats, so that useful solar heat is harvested; such as is applied to a desiccant for dehumidification process, heat driven cooling system, to heat engine; or is circulated through building.    DETAILED DESCRIPTION - An electromagnetic energy harvesting converter (1050) comprises: an enclosure having a front light transmissive cover and a rear cover; a space between the covers; an array of parallel arranged slats (1020); each having a forward face that can receive light directly, and a rear face that can receive light indirectly, and at least one photovoltaic energy converter mounted on at least part of each slat, within the spacing; and a forced air generator arranged to induce air flow (1010) within the enclosure, to remove solar heat from the slats. The forced air generator causes air near the slats to move in a direction along the length of the slats; and comprises fan within enclosure, or a high-voltage alternating current (HVAC) circulation fan outside enclosure. The slats comprise formed single ply of thermally conductive material; a sandwich of greater than or equal to 2 materials; extruded material; and/or insulation on interior side of slats, to reduce heat loss at night, and comprise electrically conductive material that connects the photovoltaic energy converters to a circuit. The slats comprise fins (1030) on rear face to increase slat convective surface area; and are positioned on pivots that allow rotation along long axes and change their orientation with respect to plane of front light transmissive cover. The photovoltaic energy converters are bonded to the slats with thermally conductive material; and form surface layers on the slats. The slat forward faces are concave to degree to allow concentration of light onto rear section of a nearby slat, are polished, and further comprise flexible linkages between the slats to allow stacking of the slats for transportation. The surface of the slat rear face comprises an optical coating that absorbs scattered light; and/or the section of the slat rear face that receives reflected light is near the outer edge of the slat. The rear cover of the enclosure is transparent. The slat geometry allows direct passage of at least some light incident to the front light transmissive cover to the rear. The transparent back of the enclosure is made of light selective transmissive material that changes the spectral characteristics of transmitted light (preferably passes longer optical wavelengths); and has an anti-reflection coating. The converter comprises an infra-red absorbing interior surface. The converter further comprises a heat exchanger (1040) at, at least one lateral end of each row of slats, and/or at least one heat exchanger in the heated air flow path; protuberances on the inside surface of the front light transmissive cover that extend perpendicularly away from the front cover to obstruct air flow near the front cover surface; slat tip obstruction bars positioned operably near to the obstruction bars mounted on the transmissive cover, and oriented perpendicular to air flow; and an automated focus system comprising a flexible linkage to the slats and a sensor control, where light intensity is used to adjust slat orientation via actuation of the flexible linkage. The heat exchanger comprises a chamber with moving fluid in it, and the chamber surface is positioned within a path of heated air that moves transverse to the slats. The spacing between the front light transmissive cover and rear cover is less than two slat widths. The front light transmissive cover is removable, and comprises an anti-reflective coating. The converter is positioned as a window beneath a ceiling with horizontal slats, where the planer slats are preferentially located at the top of the window to guide direct sunlight near the ceiling. INDEPENDENT CLAIMS are included for the following:    (1) a system comprising: the greater than or equal to 2 converters; and a fan that is connected to move air in the converters along the long length of the slats in their respective enclosures; and    (2) an automated system that responds to energy input or demand for a heat load, comprising: the converter; and further a computer, at least one sensor for detecting at least light or temperature, and at least one signal output to an actuator for adjusting slat position.    DESCRIPTION OF DRAWING(S) - The figure shows electromagnetic energy harvesting converter illustrating photovoltaic material location for concentrating light.    Air flow (1010)    Slats (1020)    Fins (1030)    Heat exchanger (1040)    Converter (1050)