Annual report pursuant to Section 13 and 15(d)

Accrued Expenses and Other Current Liabilities (Details)

v2.4.1.9
Accrued Expenses and Other Current Liabilities (Details) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Schedule of Accrued Liabilities [Line Items]    
Accrued Liabilities, Current $ 792,349us-gaap_AccruedLiabilitiesCurrent $ 243,623us-gaap_AccruedLiabilitiesCurrent
Accrued interest payable [Member]    
Schedule of Accrued Liabilities [Line Items]    
Accrued Liabilities, Current 0us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= watt_AccruedInterestPayableMember
207,945us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= watt_AccruedInterestPayableMember
Accrued compensation [Member]    
Schedule of Accrued Liabilities [Line Items]    
Accrued Liabilities, Current 425,824us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= watt_AccruedCompensationMember
19,894us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= watt_AccruedCompensationMember
Other accrued expenses [Member]    
Schedule of Accrued Liabilities [Line Items]    
Accrued Liabilities, Current $ 366,525us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= watt_OtherAccruedExpensesMember
$ 15,784us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_EligibleItemOrGroupForFairValueOptionAxis
= watt_OtherAccruedExpensesMember