GreenTech Motors, an automotive manufacturer, is considering a new venture in renewable energy solutions. The company's debt$-$to$-$equity ratio is $20\%.$ The debt currently yields $6\%,$ and the cost of equity is $11\%.$ The corporate tax rate is $30\%.$ The internal rate of return $($IRR$)$ on the renewable energy venture is estimated at $14\%,$ while the weighted average cost of capital $($WACC$)$ for firms in the renewable energy sector is $15\%.$

Estimate the WACC of GreenTech Motors. Should GreenTech Motors pursue the new venture into renewable energy solutions? Explain briefly. Show clearly each step of your calculations.