Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_2780146_6 (standard VARCHAR, pm__g_kwh_ VARCHAR)
### Question:
How many different standards have a PM of 0.02 g/kWh?
### Answer:
SELECT COUNT(standard) FROM table_2780146_6 WHERE pm__g_kwh_ = "0.02"