Solar energy, infrastructure, military cooperation and startup ecosystem are four critical areas where India can be a valuable partner to African nations, Commerce and Industry Minister Piyush Goyal said on Tuesday. The trade between India and African countries has been pretty balanced with exports of trade and services of about $40 billion (roughly Rs. 3,19,700 crore) and imports of $49 billion (roughly Rs. 3,91,600 crore), Goyal said while…