For nearly 50 years, biophysicist and inventor Mária Telkesapplied her prodigious intellect to harnessing the sun's power.She designed and built the first successfully solar-poweredhouse in 1949 but was perplexed by the knotty scientificchallenge of developing a reliable and economical way to storecaptured solar energy. Telkes held more than 20 patents at thetime of her death in 1995.