Solar collecting surfaces Posted byVesa Valtonen October 19, 2016January 30, 2019 Leave a comment on Solar collecting surfaces The future is clear. Published by Vesa Valtonen Composer Vesa Valtonen IPI 644437147. Visit my page music compositions at http://www.vesavaltonen.com in English (or http://www.vesavaltonen.co in Spanish). View more posts