What are the advantages of smart grid compared to existing power grid?

+1 vote
asked Nov 1, 2016 Question2Answer fatal error:

Reading one value from empty results

Stack trace:

require() in index.php:57
require() in qa-index.php:185
qa_output_content() in qa-page.php:830
html() in qa-page.php:380
body() in qa-theme-base.php:231
body_content() in qa-theme-base.php:354
main() in qa-theme.php:61
main_parts() in qa-theme.php:205
main_part() in qa-theme-base.php:777
q_view() in qa-theme-base.php:810
q_view_main() in qa-theme-base.php:2056
post_avatar_meta() in qa-theme-base.php:2086
post_meta() in qa-theme-base.php:1789
post_meta_who() in qa-theme-base.php:1825
qa_db_read_one_value() in qa-theme-base.php:1886